Topic: How to install E-Fans

[MoAv]

I ran across this article posted on Cafcna, written by UtahAv.  He was kind enough to give me permission to post it here for us to use.  Thanks UtahAv!!


Hi all,

This thread is my experience and impressions of the Flex-a-Lite 282 electric fans. There is much written on the site about them but very little concerning the installation. I hope this may help other members decide if the fans are a mod they would like to install and hopefully make that installation a little easier.

The Flex-a-Lite 282 electric fan kit provides you with everything you need to add 5500 CFM electric fans to a half-ton Avalanche with a 34" radiator. The fans are variable speed and are tied to the A/C system. You can adjust the fans start temperature and the fans will turn on whenever the A/C compressor turns on. The fans initially turn on at 60% speed. As the coolant temp rises for the next 10 degrees the fans will increase from 60% to 100%. The fans pull 27 amps at 100%. The fans turn on 5 seconds after the ignition switch is turned to avoid an amperage spike during vehicle startup. They run for 30 seconds after vehicle shutdown.

Installation starts with some setup work on the fans. The fan unit consists of (2) 15" fans mounted to a heavy, plastic shroud. As per the instructions you will need to mount the VSC (Variable Speed Control) to the fan shroud, drill a few holes to route wires through the shroud, attach several crimp connectors to link the two fans together and assemble several brackets to the shroud which mount the unit to factory mounting holes and tabs on the radiator.

Preliminary wiring on the back of the fan shroud.

Next you need to remove the stock clutch fan shrouds and the fan and clutch itself. The stock fan shroud is two pieces split in the middle. Remove it by either prying apart or cutting the plastic fasteners holding the two halves of the shroud together. Then remove the upper half of the shroud. Next it is easiest to remove the clutch fan. Put a wrench (I used a large, adjustable wrench) on the nut directly in front of the water pump. This is a regular thread. Then give the end of your wrench a sharp hit with a rubber mallet and the nut and fan will break free. Now you can easily unscrew and remove the fan. The lower shroud can now be bent and angled as needed to remove.

These are the parts you will remove, they are no longer needed.

Here is the radiator area with the shrouds and clutch fan removed.

Now you begin installing the new electric fan unit into the AV. The two brackets you installed on either side of the shroud earlier slide behind the two tabs on either side of the lower part of the stock radiator. The top of the fan unit attaches to the stock mounting holes previously used by the stock shroud. Once in place, press on the fan shroud until the rubber gasket on the shroud compresses about half its thickness against the radiator. Then tighten all of the mounting hardware.

The red arrow points to the lower mounting tabs on the stock radiator.

Now you can begin the wiring. Follow the included instructions and wiring diagram closely. You will wire in the included fuse box, a positive and negative wire to the battery, an ignition control wire to the fuse box, a control wire to the A/C compressor, the included thermostat probe to the radiator and the fans to the VSC box. All connections are crimp type. The hardest part of the wiring is locating and tapping the A/C control wire. The connection is made down at the A/C Compressor. I used the green wire with the white stripe. You could tap either wire as there are both positive and negative connections on the VSC box so if it doesn't work the first time just plug it into the other connection on the VSC.

The ignition control wire needs to be plugged into any fuse in the underhood fuse box that is switched and live when the ignition is ON. It must be switched or the fans would run off of the battery after the engine has been turned off. I used the fuse marked "SEO IGN" on my AV but you will want to verify that the fuse is switched using a multimeter or test probe before you decide to use it. The connection here is made using the included fuse tap.

Last you will install the included temperature probe into the radiator. You want to locate it as close to the upper radiator hose as possible for the most accurate reading. The probe simply pushes through the cooling fins in the radiator and gets capped on the front with a plastic cap. It is easiest to remove the grill and power bar assembly to install the probe. The two black wires get crimp connections and plugged into the VSC. 

 

The fuse tap for the ignition control wire.

The fuse block mounted the rail just above the radiator. Also note the black wires leading the the temperature probe in the radiator.

The install should now be complete. You will need to secure the loose wires so they don't come into contact with the fans or anything else that may damage them underneath the hood. I purchased some wire loom and put all of the wires in it to cleanup the wiring and make things easier to secure. It also gives a cleaner, professional look.

This shows the connection to the A/C compressor.

The finished install.

I purchased the fans with the hope of solving an overheating problem I was having while towing a 5000lb travel trailer. Unfortunately they didn't solve the overheating issue. I have come to realize that my overheating issue is being caused by the single core stock radiator. While I was disappointed that the fans didn't solve the overheating I am still very happy with them. The fans do keep the AV cooler in normal driving. They do help increase your mpg's and free up a bit of power that was lost running the clutch fan. When towing they help a bunch with acceleration from a stop in situations where the clutch fan would be engaged. If the AV does heat up while towing the fans will cool it faster than the clutch fan did. The fans keep the AV from heating up on very hot days while in stop and go traffic or while idling at a drive-thru restaurant. The A/C is much cooler than ever before.

Overall I love the fans and would recommend them at anyone. They just aren't the answer to overheating issues.

I hope you found this helpful to you and your AV!

-UtahAV
-Mark

[MS03 2500]

I saw that MoAV that is very detailed.

[MoAv]

I saw that MoAV that is very detailed.

I thought so too - figured it would be a real help to anyone here planning on doing this mod. 

Plus it will be easier to find for when I get around to this one of these days...

[MyBigToy]

I thought so too - figured it would be a real help to anyone here planning on doing this mod. 

Plus it will be easier to find for when I get around to this one of these days...

It's a piece of cake. The worst part is getting to the a/c trigger wire. It could easily be done at a GTG as long as the fan/clutch assembly came off.

[Main One]

His description of getting the stock fan off of the water pump is certainly much easier than what KY_Bob and I experienced with his fan.  Since Bob's truck was 6 years old, that may have something to do with it.  I brought a strap wrench to hold the pump against the torque being applied to the nut, and it still took quite a while.

You can also get, at least on the older trucks like Bob's 02 and my 03, to the a/c wire in the wire bundle that runs up and behind the alternator.  That's where Bob and I tie into it.  We tied into it there due to controlling the on/off temp through the truck's computer and the wiring harness instructions we bought to assist in doing that recommended that location.  With HPTuners and this harness, we didn't need to mount the temperature sensing unit as described above.

The flex-a-light units are nice, but I would suggest one also consider retrofitting in fans from an 05 or newer truck.  I've done those on my truck, and the flex-a-light on Bob's.  The GM fan's shrouding fits perfectly and is an easier install than the flex-a-light.  The flex-a-light is a nice kit though if you plan on controlling it via attached temp sensor as described here.  Everything comes in one package.  In my case, I bought a used GM fan/shroud assembly, a harness from Nelson Performance, and did temp setting via HPTuners.  Since I already had HPTuners, this was I believe a little less expensive route than the flex-a-light.  An if a fan motor ever goes bad, the whole fans/shroud assembly can be replaced with a stock replacement part very easily.

As far as whether the GM fans/shroud assembly would have helped UtahAv, I agree with and supplement his assessment that neither the flex-a-light or GM efans will fix the small radiator issue.

[MS03 2500]

Ok I got a question since the 2500's have a 42 inch radiator what would you folks suggest. I want a shroud but should I just make or have one made and should I go with the 282 or 292 fans. I think the 292 are a bit bigger. I want to get about 6000 cfm flow. And does anyone have one with a Trans Cooler is it effected at all.

Ok that was a bunch of question sorry

[KY_BOB]

42" ?  That's huge.  I didn't know that they were that much larger.  A 1500 AV has a 32" radiator, a lot of the 1500 Silverados have a 28".

[Main One]

Ok I got a question since the 2500's have a 42 inch radiator what would you folks suggest. I want a shroud but should I just make or have one made and should I go with the 282 or 292 fans. I think the 292 are a bit bigger. I want to get about 6000 cfm flow. And does anyone have one with a Trans Cooler is it effected at all.

Ok that was a bunch of question sorry

Sorry - I don't have any experience with the 2500s.

Something folks may want to consider doing with this mod is an alternator upgrade.  When GM started putting in the efans, they also started putting in bigger alternators.  From my experience, if you haven't added other mods drawing a great deal of current at idle, you can get by without upgrading the alternator. 

In my case, I had an always-on back-up camera and display, line-of-fire, sail-panel LEDs, and a pair of 100W driving lights which may occaisionally be on at idle.  I don't think I needed (at the time) the bigger alternator that I put on.  It is useful now though with the underdrive pulley installed on the crank, and even then, I've upped my idle rpms to give me enough juice.  I got a really good deal on my alternator out of an 05 suburban with what was quoted as less than 100 miles on it for $40 plus shipping.

[MS03 2500]

Yeah Bob it's 42 inches wide I didn't think it was that big till I measured it.

Main one I notice that problem with the Alt, in 03 they were still 105 amp with the Lux Bose NAV the sail panel lights the 55 watt headlights things were dimming at night when I would roll down the window. I went with 145 amp that comes with the snow plow package. Problem solved.

[MyBigToy]

His description of getting the stock fan off of the water pump is certainly much easier than what KY_Bob and I experienced with his fan.  Since Bob's truck was 6 years old, that may have something to do with it.  I brought a strap wrench to hold the pump against the torque being applied to the nut, and it still took quite a while.

I had no issues with my fan coming off - Mark did the same thing I did to get mine off.

The flex-a-light units are nice, but I would suggest one also consider retrofitting in fans from an 05 or newer truck.  I've done those on my truck, and the flex-a-light on Bob's.  The GM fan's shrouding fits perfectly and is an easier install than the flex-a-light.  The flex-a-light is a nice kit though if you plan on controlling it via attached temp sensor as described here.  Everything comes in one package.  In my case, I bought a used GM fan/shroud assembly, a harness from Nelson Performance, and did temp setting via HPTuners.  Since I already had HPTuners, this was I believe a little less expensive route than the flex-a-light.  An if a fan motor ever goes bad, the whole fans/shroud assembly can be replaced with a stock replacement part very easily.

I thought the shroud was a pretty nice fit on my FAL's. I got one of the fan sets that had a bad motor in it; one went out after about 1-1/2 years and I had to replace it. It wasn't a big deal but it was, if I remember correctly, about $100 for the motor. I've had no further issues in at least a couple of years since the replacement

[MyBigToy]

Ok I got a question since the 2500's have a 42 inch radiator what would you folks suggest. I want a shroud but should I just make or have one made and should I go with the 282 or 292 fans. I think the 292 are a bit bigger. I want to get about 6000 cfm flow. And does anyone have one with a Trans Cooler is it effected at all.

Ok that was a bunch of question sorry

I'm not sure if there's a size difference between the 282 & 292. The 282 fans move about 5500 cfm. I've got a trans cooler mounted in front of the radiator so it benefits from the increased airflow. It's a Tru-Cool unit and has a check-valve in it so that it's by-passed until the tranny fluid warms up.

[Main One]

It's not so much a fit issue as an ease of installation issue.  With the stock GM unit, basically slide the shroud into the tabs at the bottom and secure with the four bolts that secure the non efan shroud.

[oHIobellboy]

  I just got a set of efans for $180 shipped today..........Now I have to start looking for a bigger alternator.

[MoAv]

I just got a set of efans for $180 shipped today..........Now I have to start looking for a bigger alternator.

Hey - that's great!!  You going to do another one of those neat "photo" installs for us? 

[oHIobellboy]

Hey - that's great!!  You going to do another one of those neat "photo" installs for us? 

Looks like you've already got one here. But I'm sure I can provide a different color shot. 

[bluedevil]

Man thats cheap Mike.    Very cool...I wish i could put my hands on a set



MoAv......do you mind adding this post in the "how-to" section in resources?

[oHIobellboy]

Man thats cheap Mike.    Very cool...I wish i could put my hands on a set



MoAv......do you mind adding this post in the "how-to" section in resources?

there is another seller that has some, I think buy it now for $250 with free shipping for new ones.  Tell Trish that Christmas is just around the corner. 

[MoAv]

MoAv......do you mind adding this post in the "how-to" section in resources?

Done.   

[bluedevil]

Done.   

 

[oHIobellboy]

ok, I got my taxes back and now I'm looking at alternators. For those of you who have upgraded let me know what amperage you used and why. Also let me know what brand and why.

[oHIobellboy]

I went over to Ohio Generators today after work and talked with the guys there. I was considering one of their 8600-200 alternators ($500) but they load tested my Avy with everything running (a/c,horn compressor, hids, rear defroster and even running my slow drivers window up and down) and only pulled 80 amps and that's with a battery that didn't have a really good charge on it. They're gonna put together a 140 amp alt for less than 1/2 that for me.

[MS03 2500]

Bud GM has a 145 amp Alt, it's part of the FE3 snow plow package. All you have to do is add the right belt.

[oHIobellboy]

Bud GM has a 145 amp Alt, it's part of the FE3 snow plow package. All you have to do is add the right belt.

I'm getting this one at a good price and keeping the same belt. They also are putting a smaller pulley on it so it charges better at idle

[MS03 2500]

OK 

I just hope you don't have a Optima battery

[oHIobellboy]

OK 

I just hope you don't have a Optima battery

No Optima, looks like an  Autozone special.  What's up with the Optima that you say that?

[FlaBouy]

I have a spare 180A from AlterStart laying on my bench. Be careful with aftermarket alternators because they typically require a different size belt. My Vortech blower came with a spare belt for using with aftermarket alternators... I think I recall them being 1" longer...

E-fans are easy if you have HPT. GM also sells an e-fan harness that is factory and integrates with the underhood fuse box and works with the 2005 and up dual fans. Be careful when selecting the fans, because all fans are not equal load wise and depending on what you buy, you can melt the relays in the fan harness... ask Damon about this.... 

I did some load testing on the large fan sets for the 34" radiators and saw nearly 80A starting current and then they settled down into a 35-40A range on high with both fans kicking.. I have some test data on that somewhere. If I have time today I will dig up the link over on Allen's site where we did the testing and posted the part number of the factory GM harness. It also has some good info in there about starting/running profiles and the load test data. It gets into the relay ratings etc... I also designed a custom harness for those that want to build their own. The drawing is over there with part numbers for all the fusing and relays. You can also get a copy of all this from Damon, since I designed it for his truck when he was melting relays....

If I had access, I would link the thread over at the punk site...... 


EDIT: added pics of GM harness

[FlaBouy]

Quote from my posting on Allen's site:

Data:

Both Fans on High Start up: 87A 
FLA (Running Amp): 38A

Both Fans Low Start up: 29A
FLA (Running Amp): 9A

One Fan on Hi Start up: 55A
FLA (Running Amp): 20A

The smaller LS1 style fans like I have that fit the 27" radiator work fine with the Nelson harness. The harness is rated at 30A with the smaller fans...... I have a couple harness designs for the larger fans and we are seeing the need to thermally protect the harness in excess of 40A with the large fanset..... The isues with Pin 42 and Pin 33 are almost a mute point in most cases since there are several means to trigger the fanset with a combination of rocker/toggle switches, thermal switches driving off ECT, or just using the stock triggers that GM has programmed into the PCM.... Nice find on the 05 harness part number though... We have just purchased one to reverse engineer so our truck club members without electrical wiring experience can buy an "off the shelf" alternative to wiring ther own.....

[FlaBouy]

Here is the link to our discussions over on PT.net... MY reply #30 has the basic info, including the GM part number for the factory E-Fan Harness on the 05's that fits all our trucks...

http://www.performancetrucks.net/forums/showthread.php?t=330567&highlight=2005+PCM


"GM Parts direct has an 05 harness Part number 15216055."

[FlaBouy]

Sorry about the double, triple, and quad-druple postings.... But I had a member PM me for info on E-Fans for our truck...

Just bumped that old 2006 part number against GM Parts direct. Seems it has been superceded to a 15912581 part number....

That harness comes complete with fuses and relays for the dual fans.

[Main One]

OBB, I have put my stock alternator back on, and put on a larger pulley so that there is less load at speed, although as you have noted,  at the expense of charging power at idle.  I figured that since because of my cam I have bumped up my idle speed anyway some, it was less of an issue for me.

Through HPTuners, I not only can up my idle speed, but I have it also go higher at higher coolant temps (where the fans will kick in at low speed) and even higher at higher coolant temps when the AC compressor is on (when the fans kick in at high speed).  I set this programming up during the heat of the summer, and after having now run this through some good temp extremes, I'm thinking I can back off how much my idle increases at the higher coolant temps.

[oHIobellboy]

I have a spare 180A from AlterStart laying on my bench. Be careful with aftermarket alternators because they typically require a different size belt. My Vortech blower came with a spare belt for using with aftermarket alternators... I think I recall them being 1" longer...

E-fans are easy if you have HPT. GM also sells an e-fan harness that is factory and integrates with the underhood fuse box and works with the 2005 and up dual fans. Be careful when selecting the fans, because all fans are not equal load wise and depending on what you buy, you can melt the relays in the fan harness... ask Damon about this.... 

I did some load testing on the large fan sets for the 34" radiators and saw nearly 80A starting current and then they settled down into a 35-40A range on high with both fans kicking.. I have some test data on that somewhere. If I have time today I will dig up the link over on Allen's site where we did the testing and posted the part number of the factory GM harness. It also has some good info in there about starting/running profiles and the load test data. It gets into the relay ratings etc... I also designed a custom harness for those that want to build their own. The drawing is over there with part numbers for all the fusing and relays. You can also get a copy of all this from Damon, since I designed it for his truck when he was melting relays....

If I had access, I would link the thread over at the punk site...... 


EDIT: added pics of GM harness

I found that thread last night while I was searching for info and got the part # for the harness. Great info btw. I'll take that newer number now and look for the harness and study your pix here. I believe I can turn them on with my predator (I know I know.....dump it for HPT...someday) but I'm not sure about the limit setting availability. I know MS03 has posted about using the FAL harness without problem and I believe MBT also uses a newer harness. I like the idea of the factory harness to keep it as servicable as possible if I would have to take it into a stealer someday.

Gus at Ohio Generator told me that although I'm getting a smaller pulley the tensioner should take up the slack. We'll test that theory and see. I'm about due for a new belt anyway.

[FlaBouy]

Yeah the tensioner will take it up... for a while. You just won't get as much stretch out of it before you start hearing the squeals....

That parts number works at GMPartsDirect as of this morning. Good luck Tard... 

[oHIobellboy]

Yeah the tensioner will take it up... for a while. You just won't get as much stretch out of it before you start hearing the squeals....

That parts number works at GMPartsDirect as of this morning. Good luck Tard... 

I'm not done with you yet on this project. I'm sure I'll need a little more help.


I guess I never did post the ones I picked up off of Ebay. They're out of an 05 Silvy. I looked for the part # but I only took one off and looked it up on GMPD. It must have only been the housing number as it listed at $55.

[oHIobellboy]

I'm looking at your pix and trying to figure out where the boxes integrate.

[FlaBouy]

I'm looking at your pix and trying to figure out where the boxes integrate.

Too many moving parts? 


Ask the question.. you might be surprised.... 

[oHIobellboy]

Too many moving parts? 


Ask the question.. you might be surprised.... 

Ok,,,how does the second box attach to the first? I know you've answered this already but this will help others here that don't know where to look elsewhere.

[FlaBouy]

Ok,,,how does the second box attach to the first? I know you've answered this already but this will help others here that don't know where to look elsewhere.

I don't know.....

or better yet, let me rephrase that... I have no actual experience to speak to on that question. But I know where you can find the answer.... 

[oHIobellboy]

Did I mention that FedEx delivers on Saturdays   Now to go strip out all the wiring for the lights I don't need on here.

[WB]

Hope you get it all working!!   

[oHIobellboy]

Well the harness in the above pix is for smaller amped fans not the ones I have.

Here's the pix of the harness for the bigger fans which also has the relay block.


GM Part number is 15912597

[Alaska_AV]

Well I just got hip deep in this project

1 trip to favorite wreaking yard

06 Tahoe fans
1 complete used harness from silverado,relays an all. No idea what year, it was kinda balled up
6 matching interior trim pieces
Steering wheel radio controls
steering wheel control trim bucket
1/2 air snorkel, --cold air project

a couple other goodies, don't recall what

$160


I didn't have a wheel puller or I'd goten the clock spring also. I might go back for it tomarrow

[Fowlhunter]

The 05 efans are on my mod list and maybe someday this will get done!!  I looked on ebay last year and you could buy the fans (buy it now) for $250.  I guess I still needed the harness, I think it was like $100?  Then comes my problem, I have no way of telling the fans when to turn on and off, no tuner.   

[Main One]

The 05 efans are on my mod list and maybe someday this will get done!!  I looked on ebay last year and you could buy the fans (buy it now) for $250.  I guess I still needed the harness, I think it was like $100?  Then comes my problem, I have no way of telling the fans when to turn on and off, no tuner.   

KY_Bob can fix you up with the tune!

[Fowlhunter]

KY_Bob can fix you up with the tune!

He can do the tune on my 02??  I thought the HP Tuner was purchased for a certain year, then registered to the VIN???  If he has it for the 02 how could he tune mine, maybe register another VIN????

Thanks

[Main One]

They have changed their licensing since I purchased mine, and I believe Bob's licensing arrangement is similar to mine as well.

When I bought mine, I could buy a license for all of a model year for any given model of vehicle, times 2.  I've got an 03 Avalanche, so I can retune all 03's.  (My other license is for 04 Cadillac CTS-Vs.)  Bob's got an 02 Avalanche and I'm pretty sure he can retune any 02.  This may be limited to the 1/2 ton AVs, but I'm not sure at the moment.

[oHIobellboy]

Hey Greg, If he goes with the Flex a Lite harness I don't believe any tuning is needed. MyBigToy is using that so maybe he'll chime in here. He also has the newer VSC controller which gives a "soft start" to the fans and they don't pull that big amperage like the factory harness does. I'm starting to wish I went that route instead of the factory harness. I still need to add pins to my ecm and then turn them on with my Predator.

[Fowlhunter]

I like the OEM set up better even though it may be a pain in the  .  I like the factory look much better!

[Main One]

Hey Greg, If he goes with the Flex a Lite harness I don't believe any tuning is needed. MyBigToy is using that so maybe he'll chime in here. He also has the newer VSC controller which gives a "soft start" to the fans and they don't pull that big amperage like the factory harness does. I'm starting to wish I went that route instead of the factory harness. I still need to add pins to my ecm and then turn them on with my Predator.

Yes, I believe there are options that don't requiring running the fans through the powertrain control module.

The ecm pins, which seem intimidating, aren't that bad, especially after you have done them once!   

I wouldn't recommend trying it though for those who are intimidated by wiring up relays!   

[MyBigToy]

Hey Greg, If he goes with the Flex a Lite harness I don't believe any tuning is needed. MyBigToy is using that so maybe he'll chime in here. He also has the newer VSC controller which gives a "soft start" to the fans and they don't pull that big amperage like the factory harness does. I'm starting to wish I went that route instead of the factory harness. I still need to add pins to my ecm and then turn them on with my Predator.

OBB's right - I've got the updated VSC and no tuning is required. It's pretty much a simple plug & play. I love the soft start feature; many times a single fan will run at very low speed in city traffic, cycling on and off, up to about a 50* outside temperature. I ran my wiring inside loom and tied it in with stock routings for the most part so if you didn't know any better you wouldn't know it wasn't stock.

[Fowlhunter]

If I were to do the 05 OEM efans mod on my 02 is a larger amp alternator required, if so why?  Does anyone have a GM P/N for a larger amp alternator, once again, if so what is the P/N?

At this stage I'm working to gather as much info as possible so when the time comes I'm ready.

Thanks

[Main One]

Don't know the part number off-hand, but I bought a very-low mileage 145 amp alternator from an 05 suburban 3 years ago for $50, which included shipping.

Depending upon your electrical load (aftermarket goodies sucking power), whether you have changed your idle speed, whether you are running aftermarket pulleys, etc, you may need to get a bigger alternator.

With my cam, I needed to increase my idle speed some anyway.  I'd have to check, but I think I've put my original alternator back in the truck.  I'm running a crank underdrive pulley, and I think I've also got an underdrive pulley on the alternator.  I'll check this out this evening and get back to you - I may be needing to put one of the alternators, if it fits easily which I imagine it does, on the wife's 99 suburban.

I know that for a while I had the bigger alternator with just the crank underdrive pulley, and decided that I had enough power generating margin to either go to the smaller alternator, alternator underdrive pulley, or maybe even both.  I do have the truck set up though to idle at 875 rpm with the ac running (which with my setup always drives one of the fans at high speed when the ac is running) and the coolant temp at a temperature which would have the other fan running at high speed as well, to make sure that I'm not draining the battery.  (Both fans run at low speed if the coolant temp is up but the ac is not on, and I've currently set my idle speed to 800 rpm in this case.)

Basically, I idle at 700 or 775, depending upon whether the ac compressor is running, at 177 degrees coolant temp, which ramps up to 800/875 at 198 degrees, and have my fans set to come on at 184 and shut off at 182.  I'm running a 160 degree thermostat, which likes to keep the truck at around 180 or less as long as I've got good airflow through the radiator.

Up until a few weeks ago, I was bumping the idle speed by 100 rpm when the compressor was on, but decided to cut back by 25 rpm in those cases to these levels.

Anyway, I was needing to figure out what alternator I had in the truck anyway, and seeing which alternator pulley I have laying on the bench won't take but a minute.  I'll get the part number for the 145 amp one for you while I am at it.  You will likely need a slightly longer belt - I know I did with the bigger alternator.

[Fowlhunter]

Great info!!!
I don't have any extra goodies at this time so my electrical load should be minimal. With that said, should I plan on an upgrade or leave the factory (stock) amperage alternator in place?

 

[Main One]

OK - I am running the 145 amp alternator with underdrive pulleys on both the crank and the alternator.

I believe with both pulleys, the alternator should "see" about 530 rpm at 850.  I'm basically turning this big alternator at stock idle speeds at elevated coolant temps with the ac compressor on.

I don't have a lot of extra load.  I've got a line of fire and sail panel leds.  I haven't done the full time DRL mod, and don't usually turn on my fog lights.  Before changing my idle speed or putting on the alternator underdrive pulley, I did some test idles, monitoring what HPTuners' Scanner was telling me about loading on the alternator while turning on the high beams with my KC driving lights and my rear window defogger.  That data indicated the alternator was working pretty hard.  Been driving now for quite a while and have been backing off with the pulley and decreasing the idle speed.

If you are running a stock idle speed, I think you might be cutting it a bit close with the stock alternator.  If you could push up your idle speed some, I think I would do the install with the stock alternator and up your idle speed to 800 or more rpm.  Drive for a while and see what you think.  You may notice that your lights are dimming at idle and then think about a bigger alternator, or going even higher at idle.  If everything seems fine, you could then start experimenting with lower idle speeds.

I had a difficult time with my alternator's part number.  Finally spotted some numbers stamped into the case.  Looks like MO4MAR060 12V M, but as faint as some of those digits were, I wouldn't swear that this is totally correct.

[Alaska_AV]

Well I'm moving fwd with mine.

Can the Predator '2002 version' turn on the PCM? Anyone actually do it? Mine is going in for repair and I cant check myself.

Anyhow I have my fans running on the bench. Till I get the PCM programed I'm going to use a radiator probe to switch the system. The probe came with a relay to power the fans but I'm using the relay to give a ground input to the factory relays to turn them on. Both fans come on low, then go Apesh!t on high. Probably putting the high on a switch for when I'm towing or something. I have killed off my AC, no good as a trigger, this is flipping Alaska don't need it but for a day or 2 anyway.

[Main One]

I have very limited Predator experience so I can't answer that.

The ac compressor comes on with the defroster.  Do you have it disabled when the defroster comes on?

I believe the idea behind running the passenger side fan with the compressor running is to blow enough warm air over it to keep it from frosting over in humid weather.  Don't know how much it's needed when using the defroster.  May not be an issue in your neck of the woods.

[oHIobellboy]

Well I'm moving fwd with mine.

Can the Predator '2002 version' turn on the PCM? Anyone actually do it? Mine is going in for repair and I cant check myself.

Anyhow I have my fans running on the bench. Till I get the PCM programed I'm going to use a radiator probe to switch the system. The probe came with a relay to power the fans but I'm using the relay to give a ground input to the factory relays to turn them on. Both fans come on low, then go Apesh!t on high. Probably putting the high on a switch for when I'm towing or something. I have killed off my AC, no good as a trigger, this is flipping Alaska don't need it but for a day or 2 anyway.

NO, I just found this out tonight. My pred on my 04 will allow me to adjust the temps (if the vehicle is equipped) but not turn them on. I'm stopping by the dealer in the am to see if they can turn it on with a Tech II

The more I get into this, the more I wish I would have went with the FAL harness. install the temp probe and connect to the a/c to switch them on high.

[Fowlhunter]

NO, I just found this out tonight. My pred on my 04 will allow me to adjust the temps (if the vehicle is equipped) but not turn them on. I'm stopping by the dealer in the am to see if they can turn it on with a Tech II

The more I get into this, the more I wish I would have went with the FAL harness. install the temp probe and connect to the a/c to switch them on high.

Can one use the 05 OEM efans with the Flex-A-Lite harness?  What does the FAL harness look like?  Like I said in a previous post, when the time comes I would like to have more of a factory look under the hood.
Do you know anyone that has the HPT for the 04 that can do the tune on yours?

[MyBigToy]

The OEM fans would interface with the FAL harness - all you do is hook the fan power leads up to the harness power leads.

If you want to take a look at my harness and/or install just let me know. You can come out to the house or we can meet somewhere.

[oHIobellboy]

I don't know anyone locally that can turn my fans on with HPT and I can't justify the money for the  software without extra goodies that I can use it for. I'm waiting on a call back from the tech at the local dealer to see if he can program my ecm for me with his Tech II

[Fowlhunter]

I don't know anyone locally that can turn my fans on with HPT and I can't justify the money for the  software without extra goodies that I can use it for. I'm waiting on a call back from the tech at the local dealer to see if he can program my ecm for me with his Tech II

I can't justify spending the money for HPT either although it would be nice to have now!  So you have the 05 OEM efans and the harness from Nelson or was it a different harness?  That would be pretty sweet if the dealer could do it for a reasonable price!!  Can't wait to hear the outcome!

[oHIobellboy]

I can't justify spending the money for HPT either although it would be nice to have now!  So you have the 05 OEM efans and the harness from Nelson or was it a different harness?  That would be pretty sweet if the dealer could do it for a reasonable price!!  Can't wait to hear the outcome!

I bought a GM harness ($200) so I can tie it in all nice and factory to the ecm. I got a coulple of ecm plugs at a junk yard yesterday so I could get the pins out of it. Still waiting on the dealer to call back but I found a thread at LS1Trucks that says the general can't program the ecm to turn the fans on. I'm still waiting on a call from the dealer to confirm this.
http://www.ls1truck.com/forums/pcm-tuning-diagnostics/21864-pcm-help.html#post232047

[oHIobellboy]

Just got the call from the dealer and confirmed my thoughts. A Tech II CANNOT turn the fans on. Off to Summit I go for a FAL control module and probe.

[Fowlhunter]

Just got the call from the dealer and confirmed my thoughts. A Tech II CANNOT turn the fans on. Off to Summit I go for a FAL control module and probe.

That sucks!!!!!      Can't you purchase a tune to control the fans from Nelson and still use the GM harness???  I'm not even sure what is required to install the tune to control the fans once it is purchased??  Do you need a laptop and connect to the AV???  I guess I really don't know much???    

[oHIobellboy]

Nelson can write a tune for your avy and have the fans come on. You can also get a harness from Flex-A-Lite that has a contoller and temp probe that goes into the radiator to control the fans. Part # 31165-vsc, This is what the guy at Summit told me.
Here's the link
http://www.flex-a-lite.com/auto/html/vsc.html

[Fowlhunter]

OK, maybe now I'm totally screwed up??  Lets say I were to purchase the 05 efans and the Nelson wiring harness, the only other item I would need is the FAL VSC, P/N-31165-VSC?????????????????  Why does this sound so much easier then finding someone to tune it for me????????   

[oHIobellboy]

OK, maybe now I'm totally screwed up??  Lets say I were to purchase the 05 efans and the Nelson wiring harness, the only other item I would need is the FAL VSC, P/N-31165-VSC?????????????????  Why does this sound so much easier then finding someone to tune it for me????????  

I can't anwer the tuning end of it completely so I'm sure someone that uses HPT can give more insight into that. Look around that FAL site. I believe they have the whole harness there and you wouln't need the Nelson one.

[MyBigToy]

The FAL VSC is the whole she-bang; harness/controller/temperature probe/connectors.

(See the link OBB posted in reply #63.)

[oHIobellboy]

The FAL VSC is the whole she-bang; harness/controller/temperature probe/connectors.

I think this is the way I should have went FH. Will save you some money also.

[FlaBouy]

...... Will save you some money also.

Don't think so Tim.... my entire E-Fan mod cost me 180 bucks and that included the fans... Two years with no issues... So it might be the way you SHOULD have went because you are running into issues you didn't research prior to clicking the buy button, but FAL VSC's are NOT the cheapest way to do a fan install on our trucks. I have full control over my truck fan setpoints and shortly that will have nothing at all to do with the PCM. 

[oHIobellboy]

Didn't you have to turn the fans on with your HP Tuners though? For those of us that don't have that software I haven't found another way to enable that feature in the ECM.

[FlaBouy]

Several ways to control fans without involving the PCM... yes PCM.... Powertrain control module.... it controls the Tranny too. The Engine Control Module is in the later versions of GM products that separate the transmission away from the ECM...

Fans are controlled by relays... relays can be triggered by most anything. The trick is to kick them on and off at differing temperature set points which involves either a PCM control circuit that is looking at ECT and Ignition circuit or come up with something as simple as a $10 temp switch that is added to the circuit to kick the fans on and off around a certain temp setpoint...

Last time I checked, there were literally thousands of online sources that solve this issue for those that care to look.

But, with that said, even when I add the $10 external temp switch (which is not needed, just one way to skin a cat) and do this the hard way, that only takes me to $190 bucks... How much did you say that Flex-A-Lite setup cost?

On the HPT issue, I have set up a half dozen fan circuits for trucks other than my own. Allen Nelson will sell you a tune and a new PCM with the fan setup enabled for a fraction of what a new FAL setup cost.... Again, many ways to approach this issue for those that care to investigate...

My issue was not with which was the best way to install fans, because that will vary with the experience of the installer. My issue was with the nonsense about FAL setups being cheaper...

[oHIobellboy]

I picked up my fans off of ebay for $180 shipped, You're using an ls1 fan if I remember correctly. I know you wouldn't use something on the beast if it would not perform up to your expectations. Do you know if this is a more readily available option for other members that are considering this mod? You've already shown that it can be the cheaper route to go. Also, with the popularity of this mod and the demand going up, Do you believe it's still feasible to find those for close to the $180 you spent over 2 years ago?

[FlaBouy]

I picked up my fans off of ebay for $180 shipped, You're using an ls1 fan if I remember correctly. I know you wouldn't use something on the beast if it would not perform up to your expectations. Do you know if this is a more readily available option for other members that are considering this mod? You've already shown that it can be the cheaper route to go. Also, with the popularity of this mod and the demand going up, Do you believe it's still feasible to find those for close to the $180 you spent over 2 years ago?

Yes.... Ebay is your friend.... I would say anyone who has more than $200 in a e-fan setup has spent too much, but that is just my opinion and I am sure someone will come along shortly and point that out.

It is the easiest and cheapest route to go by a third.... Go to ChevyFullSize, PT.net, LS1truck, etc. etc. and you see this happening every day.... I have logs on my truck where in 100* weather my truck has held 185* at idle.... The one thing GM got right out of the gate was our cooling systems.

BTW, this mod is not as hard as people are making it out to be... It is actually one of the more simple mods one can do to an engine bay.

[FlaBouy]

LOL.... just to prove my answer to your question, I went and looked...  First posting on EBAY for LS1 fans... $30   

E-Fans

Other listings

$62.59
$38.55
$49.99
$75.00



Oh, btw.... Did I mention I run these fans on a stock alternator?   

Last point and I will shut up. My local Pontiac dealer uses a Tech II on my truck for things I need turned on like Radio Bypass and whatnots. I have never been charged for that service. It is a simple matter for them to turn on the fan circuit.

[Fowlhunter]

On the HPT issue, I have set up a half dozen fan circuits for trucks other than my own. Allen Nelson will sell you a tune and a new PCM with the fan setup enabled for a fraction of what a new FAL setup cost.... Again, many ways to approach this issue for those that care to investigate...

My issue was not with which was the best way to install fans, because that will vary with the experience of the installer. My issue was with the nonsense about FAL setups being cheaper...

Correct me if I'm wrong but if I had a set of 05 OEM or LS1 efans, the Nelson efan harness ($90), and a tune from them then that is a better way to go since I don't have any way to tune it myself???? 

[Fowlhunter]

I just checked Ebay, found the 05 efans, current bid is listed at $232.50.  I know FlaBouy has posted in the previous post the efans, appears they are out of an Olds, my question is would they pull enough air for the AV?  I know they are more money but the thing I like about the 05 truck fans is the fact they will pretty much drop in and look pretty much like they came from the factory.

[FlaBouy]

Correct me if I'm wrong but if I had a set of 05 OEM or LS1 efans, the Nelson efan harness ($90), and a tune from them then that is a better way to go since I don't have any way to tune it myself???? 

define "better".... 

You don't need to "tune" fans... just a way to enable the fans circuit that GM has turned off in your factory tune since your truck does not ship with electric fans. Once the circuit is turned on, there is no other requirement to go back and do anything unless, you are in my position whereas I added a 160* thermostat and a couple different external reasons to want to control where the operating range is for engine coolant....

I am not advocating either way as "better".. I am addressing "cheaper", which in my world is sometimes "better".... 

What I am saying is this. A set of LS1 fans and a nelson harness provides several advantages over other fan setups, one being the fact you do not necessarily have to go out and buy a $150 alternator in addition to everything else you are having to spend money on to get the other fans to work. To install LS1 fans, you need about 1 hour and a means to turn on the fan circuit if you want to use the PCM to trigger the fans. If you are experienced enough to figure out an alternative trigger (which is what FAL did, btw) then you do not even have to bother with the PCM....

My fans are smaller (read less current draw) and lighter than the FAL's. Performance wise there is zero difference when logged by HPT in 100* Florida sunshine... My LS1's have been on the truck since mid 2006 with zero issues...

 

[Fowlhunter]

define "better".... 

You don't need to "tune" fans... just a way to enable the fans circuit that GM has turned off in your factory tune since your truck does not ship with electric fans. Once the circuit is turned on, there is no other requirement to go back and do anything unless, you are in my position whereas I added a 160* thermostat and a couple different external reasons to want to control where the operating range is for engine coolant....

I am not advocating either way as "better".. I am addressing "cheaper", which in my world is sometimes "better".... 

What I am saying is this. A set of LS1 fans and a nelson harness provides several advantages over other fan setups, one being the fact you do not necessarily have to go out and buy a $150 alternator in addition to everything else you are having to spend money on to get the other fans to work. To install LS1 fans, you need about 1 hour and a means to turn on the fan circuit if you want to use the PCM to trigger the fans. If you are experienced enough to figure out an alternative trigger (which is what FAL did, btw) then you do not even have to bother with the PCM....

My fans are smaller (read less current draw) and lighter than the FAL's. Performance wise there is zero difference when logged by HPT in 100* Florida sunshine... My LS1's have been on the truck since mid 2006 with zero issues...

 

My bad, better as meaning cheaper is what I maent, I should have said that.   

OK, so if I were to purchase a set of (05 OEM or LS1 OEM) efans, the harness from Nelson, then all I need is to have someone enable the fans circuit?  Once this circuit has been turned on then the fans should work (turn on and off at the correct temp depending on the t-stat) just like they would from the factory???  I know there was discussion of the dealer not being able to "tune" this mod but do you know if they have the capability of enable the circuit for the efans?  This probably seems like I continue to ask the same dumb  questions but I want to make sure I have all the bases covered.

Thanks so much!!!    

[FlaBouy]

OK, here's the visual.....

Here is how you truck is shipped from the factory in the tune....

Notice No fans and everything set High so no circuits energize...

[FlaBouy]

This is what I changed to enable my fans and set the operating limits.... This takes about 30 seconds to set up and a minute and a half to upload....

Then walk away and forget about the fans.... They will know when to turn on and turn off, even with a 200 second delay after the truck is shut off...

[FlaBouy]

I should have mentioned something about my setpoint. I run a 160* thermostat.... With a 160* thermo, the truck will basically hold 180* with the thermal effiencies of the cooling system on a stock truck. GM runs Tstat temps of 210 to deal with any water or moisture issue that may be in the fuel and deal with another couple of emissions related issues. I prefer to run my truck at 180* to help a bit with the 135* hair dryer I have on my truck.

So I set my fans at that 180* mark for the first fan and bring the second fan in on 190*... Like I said.... Find someone at a GTG that has HPT or EFI LIve for your model year. The last set I did was for ZooJelly. He did not even have his fans installed yet. I jacked in, set the fan trigger and logged out. When he got around to installing the fans, they worked as soon as he plugged them in....

Easy as that....

[FlaBouy]

Or this just occurred to me....

For the money you spend on a FAL unit, buy a set of LS1 fans, harness and HP Tuners and do it yourself... at least when you are done you will have e-fans and the ability to tune your truck....

 

[FlaBouy]

I just checked Ebay, found the 05 efans, current bid is listed at $232.50.  I know FlaBouy has posted in the previous post the efans, appears they are out of an Olds, my question is would they pull enough air for the AV?  I know they are more money but the thing I like about the 05 truck fans is the fact they will pretty much drop in and look pretty much like they came from the factory.

Those 05 fans will require a larger alternator.... They draw nearly 90 amps on startup vs.  30 amps on the LS1's... which is why BBA and others were burning Nelson harnesses up with the 05 fans....and yes, I have found that the LS1 fans are quite sufficient in daily driven 100* Florida heat....

The ebay links I talked too were all different setups... Olds, WS6's, etc... all pretty much the same....


Here is the info I posted a few years ago on Allen Nelson's site:

Data:

Both Fans on High Start up: 87A  
FLA (Running Amp): 38A

Both Fans Low Start up: 29A     
FLA (Running Amp): 9A

One Fan on Hi Start up: 55A    
FLA (Running Amp): 20A

The smaller LS1 style fans like I have that fit the 27" radiator work fine with the Nelson harness. The harness is rated at 30A with the smaller fans...... I have a couple harness designs for the larger fans and we are seeing the need to thermally protect the harness in excess of 40A with the large fanset..... The isues with Pin 42 and Pin 33 are almost a mute point in most cases since there are several means to trigger the fanset with a combination of rocker/toggle switches, thermal switches driving off ECT, or just using the stock triggers that GM has programmed into the PCM.... Nice find on the 05 harness part number though... We have just purchased one to reverse engineer so our truck club members without electrical wiring experience can buy an "off the shelf" alternative to wiring ther own.....

[MyBigToy]

And do you even want to bring up why there is a difference in the MAP curves? 

[FlaBouy]

I already did... one is from a stock tune and one is from my truck, which has not been stock for quite a while now....

Oh, wait.... I still run a stock radiator.....   


EDIT: But if I were of the inclination to comment about the increased airflow and VE efficiencies between the two of those MAPS, I would be inclined to interject the argument that the additional airflow around idle and through 4000 rpms would suggest massive torque and horsepower difference between the two tunes, but we all know that cannot be so since my hairdryer cannot make torque below redline....   

[FlaBouy]

I thought it was a SNAIL. I can't imagine anyone saying a snail couldn't make torque/hp under redline. I seem to have a generally foggy memory of someone saying that as-delivered, snails vs heat generators, snails deliver increased torque/hp much higher on the rpm curve. And that's the last I'll remember about that! 

If you consider much higher up the rpm scale about 100 rpm's then you would be correct right up until 3500 rpm in which you would be wrong again....

cammed hair dryer on the left. cammed heat generator on the right....  I guess that's what you get for listening to "someone"....

I had to cut off the top of both of these for obvious reasons... didn't want to embarrass the heat generator... 

[Fowlhunter]

I should have mentioned something about my setpoint. I run a 160* thermostat.... With a 160* thermo, the truck will basically hold 180* with the thermal effiencies of the cooling system on a stock truck. GM runs Tstat temps of 210 to deal with any water or moisture issue that may be in the fuel and deal with another couple of emissions related issues. I prefer to run my truck at 180* to help a bit with the 135* hair dryer I have on my truck.

So I set my fans at that 180* mark for the first fan and bring the second fan in on 190*... Like I said.... Find someone at a GTG that has HPT or EFI LIve for your model year. The last set I did was for ZooJelly. He did not even have his fans installed yet. I jacked in, set the fan trigger and logged out. When he got around to installing the fans, they worked as soon as he plugged them in....

Easy as that....

Very cool!!  I thought the fans would need to be installed prior to enabling the circuit?

[Main One]

Those 05 fans will require a larger alternator.... They draw nearly 90 amps on startup vs.  30 amps on the LS1's... which is why BBA and others were burning Nelson harnesses up with the 05 fans....and yes, I have found that the LS1 fans are quite sufficient in daily driven 100* Florida heat....

The ebay links I talked too were all different setups... Olds, WS6's, etc... all pretty much the same....


Here is the info I posted a few years ago on Allen Nelson's site:

Data:

Both Fans on High Start up: 87A  
FLA (Running Amp): 38A

Both Fans Low Start up: 29A     
FLA (Running Amp): 9A

One Fan on Hi Start up: 55A    
FLA (Running Amp): 20A

The smaller LS1 style fans like I have that fit the 27" radiator work fine with the Nelson harness. The harness is rated at 30A with the smaller fans...... I have a couple harness designs for the larger fans and we are seeing the need to thermally protect the harness in excess of 40A with the large fanset..... The isues with Pin 42 and Pin 33 are almost a mute point in most cases since there are several means to trigger the fanset with a combination of rocker/toggle switches, thermal switches driving off ECT, or just using the stock triggers that GM has programmed into the PCM.... Nice find on the 05 harness part number though... We have just purchased one to reverse engineer so our truck club members without electrical wiring experience can buy an "off the shelf" alternative to wiring ther own.....

My first hand experience with the 05 truck fans and a Nelson harness:

Had to replace a relay after over a year of use - no other issues to date.  Noticed temps getting too high in stop and go traffic.  Been using this setup for 3 years now.

[FlaBouy]

Check the rating on those relays and see if you have his version 1 harness or version 2... The version 1 harnesses are where the issue is at because he originally designed that harness for the LS1 27" dual fans only.... He upgraded the harness when people started throwing the 05 fans at the old harness...

This is well documented on his site and PT.net....


One of literally hundreds of threads on issues with running 05 fans and the Nelson Harness....

http://www.ls1truck.com/forums/electrical/10373-nelson-harness-took-crap-me.html

It also suggest if you run 05 fans, then run a factory harness.... see post # 5

that thread also gets into the "modified" Nelson harness for the 05 fans... see post #8.

That is from Nelson's forums......

EDIT.. It also gets into how the factory harness is plug and play from a member that bought and installed it... see post #15.... 

[Alaska_AV]

LOL.... just to prove my answer to your question, I went and looked...  First posting on EBAY for LS1 fans... $30   

E-Fans

Other listings

$62.59
$38.55
$49.99
$75.00



Oh, btw.... Did I mention I run these fans on a stock alternator?   

Last point and I will shut up. My local Pontiac dealer uses a Tech II on my truck for things I need turned on like Radio Bypass and whatnots. I have never been charged for that service. It is a simple matter for them to turn on the fan circuit.

LOL, I about pooped myself when I clicked your link


check out the shiping to me,
US $115.79
UPS Ground
Service to 99687, United States

Almost as much as what I paid for my fans


Just saying WOW

[FlaBouy]

No hablo english fedex.... 



Have Sarah throw them on her private jet next time she is down.... 

[Alaska_AV]

The fans are in. ER... phase 1

I tried out the old Predator, It worked this time and unbricked my Predator only PCM It can not turn on the fans. the operating temp can be adjusted though.

I still want a PCM controlled system but till then I was going to use a radiator probe. Till it came loose during the test drive, then broke in 2 while tightening the probe back onto the switch. So now they are triggered but ignition power , on low speed, till I get the PCM turned on.

until I mail 2 PCM's to Arizona and back, I'm still under $200 and that includes 2 other big mods........

[FlaBouy]

The fans are in. ER... phase 1

I tried out the old Predator, It worked this time and unbricked my Predator only PCM It can not turn on the fans. the operating temp can be adjusted though.

I still want a PCM controlled system but till then I was going to use a radiator probe. Till it came loose during the test drive, then broke in 2 while tightening the probe back onto the switch. So now they are triggered but ignition power , on low speed, till I get the PCM turned on.

until I mail 2 PCM's to Arizona and back, I'm still under $200 and that includes 2 other big mods........

Have you tried going by the GM or pontiac dealer and have them turn the on with a Tech II? I am willing to bet the can turn them on and you can use your Predator to set the temp points...

Just a thought...

[FlaBouy]

Back to the efan discussion...

I should have my head examined for posting this because someone will come along and want to argue about it...

A Fan switch from a Chevy citation will work in some cases as a fan trigger. When the engine reaches the preset temp it will turn the fan on and then shut off when it drops down. The sensor will complete a path to ground so all you need to do is wire up a relay with 12V switched and then the sensor does the rest. You can also install a manual override switch if you want to.

Switch number is AC Delco # 15-5403

[MyBigToy]

BTW, do you have anything productive to add to the e-fan conversation or do we need to discuss blowers more?

I already gave my input - FAL and/or VSC. If you try to go the alternative route and don't already have tuning software, you end up with the issues OBB ran into. Dealerships are reluctant to activate the PCM pins (they say they can't or that it's a liability issue). You're then stuck activating the fans with the ignition or a switch. Or you buy a stand-alone controller like the VSC or another. Or you try to find someone who has tuning software that is willing to use their licenses to tune your PCM. Or you buy tuning software and have to learn how to use it (this could be viewed as a positive, depending on your outlook). Or you pull the PCM and send it out to have it tuned. By that time you could have just bought the FAL 282s or other brand stand-alone fans, installed them, and been done with it. I bought my 282 fans used, never installed, for $300. They've been on the truck for at least 4 years now with no issues except replacing one motor that had a bad bearing (FAL had a bad batch of motors).

The 282s flow 5500 cfm - how much do the LS1/LT1 fans flow? Why do I ask? It's a consideration for anyone who tows a heavy load as e-fans supposedly aren't a good idea for towing. Several members have had issues with e-fans when towing on long, sustained uphill grades and had to add a larger-capacity radiator to solve the issue. It's a guarantee that the LS1/LT1 fans flow less than the 282s. I don't know what the 05+ OEM fans flow but I bet it's as much or more than the 282s. I've had no issues so far when towing, including the 5k+ lb travel trailer, and the temperature gauge never moved from the 195* set point.

[Main One]

I don't know how much the 05+ truck fans flow, but suspect that they do flow more than the LS1 fans.  Don't know how well they would compare to your 282 fans.

I have seen cases where I've gotten some elevated temps with the truck fans, although for me, elevated is above 190 degrees.  Idling, stop and go traffic in 100+ degree heat, isn't where I see it.  I see it when climbing hills, without towing anything.  I-65 in southern Tennessee and northern Alabama, with cruise control set in the upper 70s, I will see my temp gauge climb, although the point to where it climbs is about where the truck operated with the stock thermostat.  I also see it climb when driving up to our condo above Gatlinburg, TN.  It is in the city limits, but is purportedly 1600' above the strip in downtown Gatlinburg.  One of my wife's cousins, who has ridden the Dragon's Tail stretch of 2-lane road within an hour of Gatlinburg on her Harley reported that road is nothing compared to the road up to our condo.  It is quite a climb.  Coming down, if you don't downshift, and come down in let's say a rather "spirited" fashion, you will be smelling your brakepads when you get to the bottom, I know I have.  With the higher stall-speed converter in the truck, I come down in 2nd gear, used to use 3rd with the stock converter.  The point being here that you are climbing over a quarter mile in about 10 minutes, with enough twisties in it there you are never seeing more than about 25 mph of ambient airflow through the radiator, and a great deal of time you are doing 15, +/- 5, mph.  I think the only time that I now hear the fans running after I shut the engine off - have them set to stay on for 30 seconds if coolant temp is above 194 when I shut off the engine, is when I go to the condo.  I've done a scanner log with HPTuners, and seen coolant temps above 200 degrees after reachiing the condo.

IMHO - hill-climbing and towing are the big cooling-system concerns.  If I was running a stock thermostat, I might not see any issues.  However, if I was, I might be seeing temps climb above "normal".  With my current setup, I've got a pretty good amount of margin for temps to increase before they get above normal for a stock engine.  I believe that for most applications, efans should work fine.  It sounds like FlaBouy gets good performance out of his LS1 fans.  Don't know how much towing he's done with them, or hill-climbing.  I would have to believe that he has done some of both, and he hasn't seen any issues.

I will also add that our, or at least my, temp guage is not very good, as compared to the data the computer is seeing and relayed to me via the HPTuners scanner.  My guage "starts" at 160, but it starts moving if memory holds correct before the temps go above 140.  The mark midway between what looks like should be 160 and 210 on the guage, for me, is where the needle likes to park itself whenever it is at 175 +/- 5 degrees.  Above 180, it will move above this mark pretty rapidly.  Looking at the guage and the numbers on it, one would think that where it parks should be at about 185.  At 185 however, the guage is now reading in the neighborhood of 190-195.  Climbing up to the condo, my guage will get up just past what looks like 210 on the guage, but is really in the 200-205 range.

[Alaska_AV]

I have been watching my temp with my predator. she runs 192-195, the dash gage reads just over 200, it's kinda confusing anyhow. I have the fans running low with the ignition , temporally.

I talked to, 2 dealers today about turning on the PCM. the first one blew me off. with a quick NO. The second was , we can try. Pay first, well over $100.... WTF they have reprogrammed a used PCM for $80 for me before. guess they have a light bill to pay....... I hope they miss a payment, their fricking lot lights, light up my kitchen a mile away all night. Don't need to turn on my lights to do dishes at 2 am.........

Just curious were would you put the Chevy citation switch? Not that I have looked hard but I haven't noticed any spare holes anywhere for a twist in.

I'm very happy with the route I'm going with the fans. Just trying to avoid doing what I know I have to do....LOL I hate easy outs......

BTW one of the crack heads didn't even think the fans and harness would fit in my 02. He declined to look under my hood!

[Main One]

FlaBouy can be rather irritating at times, but I've never known him to be wrong on a technical issue.

[Main One]

Got the following passed to me from FlaBouy who asked that I post it here:

Talked with a buddy of mine in great detail about the tech II capabilities in regards to the fans. The best we can tell the tech II will allow the technicians to toggle the fans on and off for troubleshooting purposes in real time; that is, the ones who can manage to figure out how to burrow down to the fan menu? most can?t? With that said, best I can tell, without a pre-tuned setting to drop, the technician either does not have the capability to make the change permanent; or, they will not have the expertise to save the settings and reflash the PCM. Not saying that it is impossible to do with a Tech II, but I would suspect there is about a 1% chance finding a technician with the skills to accomplish this?..  So he is back to finding someone who can reflash the truck using HPT or EFI Live? or adding an external means like the temp switch or some other means to toggle the fans?

[KY_BOB]

He can do the tune on my 02??  I thought the HP Tuner was purchased for a certain year, then registered to the VIN???  If he has it for the 02 how could he tune mine, maybe register another VIN????

Thanks

Yes, I can.

You can license either a single VIN or a complete year and model.  I'm licensed for all 2002 AV's.  I've tinkered with Earthquake and Quarter's '02s.

[MyBigToy]

Yes, I can.

You can license either a single VIN or a complete year and model.  I'm licensed for all 2002 AV's.  I've tinkered with Earthquake and Quarter's '02s.

Good to see you back on-line, Bob. Don't be such a stranger. I understand you've been a little busy with yard work and insurance work.

I should be first in line to have some modding done to my PCM. I've been trying to get you to come to St. Louis again since the first Bratfest. Maybe between Fowlhunter and I we can coerce you to come up!

[KY_BOB]

Good to see you back on-line, Bob. Don't be such a stranger. I understand you've been a little busy with yard work and insurance work.

I should be first in line to have some modding done to my PCM. I've been trying to get you to come to St. Louis again since the first Bratfest. Maybe between Fowlhunter and I we can coerce you to come up!

How about you guys come to KY, I'll tinker with your computers, and you guys can build me a new deck 

[MyBigToy]

How about you guys come to KY, I'll tinker with your computers, and you guys can build me a new deck 

Are you sure you would trust a deck that I built?  Remember - I have a farm and there's nothing you can't build with baling wire and duct tape!

[MS03 2500]

How about you guys come to KY, I'll tinker with your computers, and you guys can build me a new deck 

Hummm  throw in a boat ride with the eye candy and I'll think about it.   

[Fowlhunter]

Hell I'm game, but lets not forget the cold beverages!!!!!!!!!     

[Main One]

Bob,

This is starting to look like an 02 & 03 tuning & deck building gtg.  I'll bring my laptop!

[Alaska_AV]

Well it looks like I'm sending my PCM's to ItsStopher in Nevada. I have 2, one stock and one I use the predator on. I'm going to send one at a time. So we don't have issues with the crank relearn I'm sending mine down. He has the HP tuner and did his and others.  He has the 02 licensees

just did 100 mile trip to day and she stayed at 195 ish, I assume that is the stock T-stat temp

[Main One]

Well it looks like I'm sending my PCM's to ItsStopher in Nevada. I have 2, one stock and one I use the predator on. I'm going to send one at a time. So we don't have issues with the crank relearn I'm sending mine down. He has the HP tuner and did his and others.  He has the 02 licensees

just did 100 mile trip to day and she stayed at 195 ish, I assume that is the stock T-stat temp

Sounds like a good plan!   

[KY_BOB]

Hummm  throw in a boat ride with the eye candy and I'll think about it.   

I'm not sure that I talk any of the eye candy into getting on the boat until it warms up a little.

Hell I'm game, but lets not forget the cold beverages!!!!!!!!!    

That is NO problem. 

[oHIobellboy]

WB has done some homework for us that have Predators for tuning and I've been nosing around the Diablsport forum as well.
 It appears that Mikel can write a custom tune for your Pred that can turn the fans on.  Fowlhunter and myself have also contacted Nelson Performance about getting some programming done with the pcm's. Will post more when I have an update.

[Alaska_AV]

well that would be cool. I need to update my predator anyhow.

how much?

[oHIobellboy]

well that would be cool. I need to update my predator anyhow.

how much?

Dunno. I havn't checked back in on that board yet.

[WB]

well that would be cool. I need to update my predator anyhow.

how much?

To update a U7193 to a U7193 with logging capabilities is $100.  I still use poor man's logging!   

I don't think they charge for little things in custom tunes like hard shifting etc...At least they didn't charge me when they did it for me.

[WB]

What pins on the PCM need activated to use electric fans in the 2004 AVy??

Anyone know?? Is there a pinout diag for the PCM???

WB

[oHIobellboy]

What pins on the PCM need activated to use electric fans in the 2004 AVy??

Anyone know?? Is there a pinout diag for the PCM???

WB

on C1 is it pin 42 and on C2 it is pin 33

I found it on ls1trucks,  HERE

[WB]

on C1 is it pin 42 and on C2 it is pin 33

I found it on ls1trucks,  HERE

 

OK ..your all over it now.....I'll shut up!! 

WB 

[oHIobellboy]

OK ..your all over it now.....I'll shut up!! 

WB 

I had just posted this over at DS when I found  it and then popped back on here.

[Alaska_AV]

boy that got all jacked up at DS.

I registered for the forums but now I cant get to the site.... I hate computers....

So I'm guessing, I talk to the one guy and upload my stock tune. tell em what pin i need turned on. They may just do it and email the tune back. without all that updating stuff? An charging A but load of $$$$ i don't have right now?

[oHIobellboy]

boy that got all jacked up at DS.

I registered for the forums but now I cant get to the site.... I hate computers....

So I'm guessing, I talk to the one guy and upload my stock tune. tell em what pin i need turned on. They may just do it and email the tune back. without all that updating stuff? An charging A but load of $$$$ i don't have right now?

I would say nose around over there first and see if you can find any one else with an 02 Pred that's had it done. Also, check out LS1Trucks for threads in there. My Daughter has a JR ROTC competition this am or I'd go looking to help you out.

[WB]

boy that got all jacked up at DS.

I registered for the forums but now I cant get to the site.... I hate computers....

So I'm guessing, I talk to the one guy and upload my stock tune. tell em what pin i need turned on. They may just do it and email the tune back. without all that updating stuff? An charging A but load of $$$$ i don't have right now?

HUH??

Can't get to the DS site??

What's up with that?

What happens??

WB

[Fowlhunter]

I'll try to get back on board later today or tomorrow, I have a fundraiser to go to all day today!!   

[Alaska_AV]

HUH??

Can't get to the DS site??

What's up with that?

What happens??

WB

I dont know, probly my broswer. After awile It just wont load the pages and I get the 'internet explorer cant open page' It happens here also. usually when I try to post.

[WB]

I dont know, probly my broswer. After awile It just wont load the pages and I get the 'internet explorer cant open page' It happens here also. usually when I try to post.

BUT....I saw you on the board over there....your using the same name...   

[Alaska_AV]

  I was on for awile today, posted, then it went to shit on me.  Just happend at clubavalanche to me again....... ugg

[WB]

I was on for awile today, posted, then it went to shit on me.  Just happend at clubavalanche to me again....... ugg

It's got to be on your end....computer..modem..or service...   

I can see your post on DS!!

[Alaska_AV]

Well I talked to Chris 'ItsStopher'. the guy I was going to send my PCMs, He has an 02 AV and factory fans run by the PCM done by his hp tuners. he replied that he turned on pin 42 on the blue connector.
The fans turn on at 220 and off at 210 with the stock tstat.

OK I'm ready for DS

guess I'll try to copy my toon Sunday. This is kinda exciting. in a plan coming together type of way.

[WB]

Well I talked to Chris 'ItsStopher'. the guy I was going to send my PCMs, He has an 02 AV and factory fans run by the PCM done by his hp tuners. he replied that he turned on pin 42 on the blue connector.
The fans turn on at 220 and off at 210 with the stock tstat.

OK I'm ready for DS

guess I'll try to copy my toon Sunday. This is kinda exciting. in a plan coming together type of way.

Just to make this thread clear.  You only need to do the $100 upgrade to a predator u7193 to do internet updates to the TOOL or to get electronic logging abilities.

You CAN copy your tune to your PC and email it to DS to get the PCM enabled by custom tune, after you co-ordinate what you need from DS, without upgrading the tool.

 

WB

[Fowlhunter]

I just put my final bid in on the OEM 05 electric fans on Ebay.  I really want these fans but I will not go any higher, I'm already a little higher than the buy it now price they had listed a few weeks ago.  I'll keep you all posted!

[Fowlhunter]

The 05 OEM (New) electric fans from Ebay are mine!!

 

[Main One]

Congrats!  Too bad you didn't do the Buy it Now!   

[Fowlhunter]

Congrats!  Too bad you didn't do the Buy it Now!   

I know, I wish I would have pulled the trigger a few weeks ago, I could have saved $10!!!!  I called them to see if they had any of the buy it now at the $250 price but they didn't. 

[Alaska_AV]

Woooh hooo

DS has sent me 2 tunes to try loading with the Predator. I have to wait till the weekend to try em..... 

[oHIobellboy]

Woooh hooo

DS has sent me 2 tunes to try loading with the Predator. I have to wait till the weekend to try em..... 

I've got a couple also from them today. I've got to put the pins in the pcm and then check them when the temps rise to see which tune works. I might have sent the wrong tune to them but they've figured it out. 

[Alaska_AV]

OBB, ya I have to do the same stuff. I think I sent them a copy of my back up but I realy don't have a clew!!!! 


good luck!!!

[oHIobellboy]

OBB, ya I have to do the same stuff. I think I sent them a copy of my back up but I realy don't have a clew!!!! 


good luck!!!

Yeah,,,time to do some more studying over there. As soon as I plug in the pred it starts copying one tune to the pc. We'll have to look into this some more. I know those guys over  there at Diablosport.com are working with us pretty diligently.

[Alaska_AV]

have you clicked the interupt/stop  button in the 'file' above the download button

Just thinking is still trying to upload on ya?

[WB]

When they did a custom tune for me, they wanted the factory backup file.   

[Alaska_AV]

theres a 50/45 chance they got that from me

[Alaska_AV]

YYYYYYYYAAAAAAAAAAAAAA HHHHHHHHHHHHHHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


IT WORKS!!!!!!!!!!


My AV runs it's self!!!!!!!!!!!!


Thanks WB, OBB. and everyone else. It's time for me to Fubar somthing else now!

[WB]

YYYYYYYYAAAAAAAAAAAAAA HHHHHHHHHHHHHHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


IT WORKS!!!!!!!!!!


My AV runs it's self!!!!!!!!!!!!


Thanks WB, OBB. and everyone else. It's time for me to Fubar somthing else now!

COOL man, glad you like it.  Now you need a DiabLew tune!! 

[oHIobellboy]

06MonteSS helped me out a lot today. I sent the wrong file to MikeL and Johan...uploaded it and now the ecm will turn the fans on...Looks like good weather this weekend for the rest of the install.

[Main One]

Way to go!   

[Fowlhunter]

06MonteSS helped me out a lot today. I sent the wrong file to MikeL and Johan...uploaded it and now the ecm will turn the fans on...Looks like good weather this weekend for the rest of the install.

Tracking number says my efans should be here today!!!  So your Predator will turn on the fans?!?!  Awesome!!!  What do you have left to install?? 

[Alaska_AV]

If anyone needs a pin to put in the 2002 pcm, I have 50+ of them

used with about 1 foot of wire.

[oHIobellboy]

Tracking number says my efans should be here today!!!  So your Predator will turn on the fans?!?!  Awesome!!!  What do you have left to install?? 

Everything else..LOL, I havn't put anything in yet until I knew what was going on with the ecm.

If anyone needs a pin to put in the 2002 pcm, I have 50+ of them

used with about 1 foot of wire.

Here's a few pix of what A_A is talking about.
Got this from a junk yard for $5.


Took it apart to get the pins I needed and added some more wire to it.



Then had to take apart the ones on the truck CAREFULLY to add the pins in the correct places.

[WB]

AWESOME!!  Git 'er Done!!   

[Alaska_AV]

just a FYI. the pins are allot easier if inserted from the front. First poke a small Allen wrench in the hole to open the rubber weather seal on the back side. then push in the wire till the pin locks in. replace blue cap locking them all in.

even removing from the donor plug. Release the wire from any harness material. release the tabs on the sides of the blue cap, wiggle your preferred color wire and pin will pop out the front. pull wire through.

I hope this helps someone

[Fowlhunter]

OK, this may sound like a dumb  question but what is that, the ECM or PCM and why are you adding pins????   

If this is the PCM, I thought one could be purchased from NP ($35) to turn on/control the efans???  Why do I feel like I'm in the dark as to what I need to do now???   

[oHIobellboy]

The ecm harness in your 02 (and my 04) does not have the wiring coming from the ecm to the fuse box. You have to add them. A_A also has an 02 so he would be able to help you with which pins you would have to add. Even if you get the ecm swap from NP with the fans turned on, It won't do any good until you put the wires in to go to the fan harness.

[Alaska_AV]

ECM/PCM.... were talking the same thing , engine control/power control    With programing and adding a pin to to the wiring harness going to it Our trucks can run the Fans. On the 2002 AV you add a pin to slot 42/blue connector. Program the ecm/pcm.  It will give you a ground signal to activate the fan relays.


The other choice is to use an aftermarket control harness. Witch has a temperature probe that you put through the radiator. This also runs the relays that power the fans. this is usually a +positive trigger


either way works. But I love telling my service guy at the dealer.... I did it with out him, AGAIN

[Fowlhunter]

If anyone needs a pin to put in the 2002 pcm, I have 50+ of them

used with about 1 foot of wire.

Did someone say they had extra pins??  How many are needed and where does the wire or wires need to go to?  My guess is you soldered the pins on to a piece of wire?

[Fowlhunter]

The ecm harness in your 02 (and my 04) does not have the wiring coming from the ecm to the fuse box. You have to add them. A_A also has an 02 so he would be able to help you with which pins you would have to add. Even if you get the ecm swap from NP with the fans turned on, It won't do any good until you put the wires in to go to the fan harness.

OK, I understand but where does the other end (non pined) of the wire go to?  I know you said fuse box, are you referring to the fuse box under the hood?  Are the wires added kind of like the diodes for the lighting mods, Insert the non pined end of the wire under a relay or are they added somewhere else???

[oHIobellboy]

Did someone say they had extra pins??  How many are needed and where does the wire or wires need to go to?  My guess is you soldered the pins on to a piece of wire?

Look at my pix again......you'll see in one of them some red shrink wrap and two different colored wires. When you take a pin from the old ecm you  leave a tail on it to solder an extension piece onto it. The end of that will then go into the harness that you get from Nelson or GM (there should be a wire going to the relay you tie into).  I'll get some more pix once I get my fans done.

[Alaska_AV]

Did someone say they had extra pins??  How many are needed and where does the wire or wires need to go to?  My guess is you soldered the pins on to a piece of wire?

PM me your address and I'll put one in snail mail to ya

The other end goes to the relays that you need to run the fans. I put mine in the stock place under the fuse box cover.

Again the PCM gives a negative/ground to triger the relays. Most aftermarket relays are trigared buy power/positive.  Very important but easy to work around

[Fowlhunter]

Look at my pix again......you'll see in one of them some red shrink wrap and two different colored wires. When you take a pin from the old ecm you  leave a tail on it to solder an extension piece onto it. The end of that will then go into the harness that you get from Nelson or GM (there should be a wire going to the relay you tie into).  I'll get some more pix once I get my fans done.

I see that but I thought the NP harness came with a pinned wire?  I'll have to look at it and read the installation instructions again.

Thanks Man!!!

[Fowlhunter]

PM me your address and I'll put one in snail mail to ya

The other end goes to the relays that you need to run the fans. I put mine in the stock place under the fuse box cover.

Again the PCM gives a negative/ground to triger the relays. Most aftermarket relays are trigared buy power/positive.  Very important but easy to work around

Like I just asked OBB, I thought the NP harness came with a pinned wire but I may be wrong?  Is that the same place I did the 02 full time DRL mod?  I did that on the green or blue square block, I had to swap wire locations.

Thanks Man

[oHIobellboy]

Like I just asked OBB, I thought the NP harness came with a pinned wire but I may be wrong?  Is that the same place I did the 02 full time DRL mod?  I did that on the green or blue square block, I had to swap wire locations.

Thanks Man

I don't know about the nelson harness coming with a pnned wire. I do know it does not go into the fuse block. It HAS to go into the pcm.
This pix is a couple of pcm plugs that I got from a slavage yard.


This is where the ecm is located. note the battery in the pix, it is just below that. You'll also note the 2 wires that i have hanging out of the pcm plugs until I get the fans installed and then these wires will be put into the harness.


This pix shows the cover pulled back (yellow) and the plugs that plug into the pcm (blue)


This is a pix that shows (kinda) where the factory harness plugs into the pcm.



On the harness that you will buy (either NP or GM) the relays on that harness will go under the fuse box cover. You will have to take out the cross brace from the fender to the firewall to get that cover off. I'm looking for that pix now.

[oHIobellboy]

Reply #42 in this thread has the pix of where the factory placement of the relays are. pix 3 and4

[Fowlhunter]

Look at my pix again......you'll see in one of them some red shrink wrap and two different colored wires. When you take a pin from the old ecm you  leave a tail on it to solder an extension piece onto it. The end of that will then go into the harness that you get from Nelson or GM (there should be a wire going to the relay you tie into).  I'll get some more pix once I get my fans done.

Take a look at the attached NP harness installation instructions, I'm pretty sure this comes with the pin for pin slot 42 on the blue connector?  Read the instructions under #5. 

 

http://www.nelsonperformance.com/harness/Harnesslnstall.pdf

[Alaska_AV]

according to that they supply the pin for the PCM. so I dont need to send you one


Who is programing your PCM to run that pin?

[oHIobellboy]

Take a look at the attached NP harness installation instructions, I'm pretty sure this comes with the pin for pin slot 42 on the blue connector?  Read the instructions under #5. 

 

http://www.nelsonperformance.com/harness/Harnesslnstall.pdf

that should save you needing to add pins then......Make sure you tell them you got the Tahoe fans, this is a 2 fan setup as opposed to the LS1 single fan setup. There is a difference as there should be two pins instead of just one. Also on that note. The Tahoe fans draw more amps so it should be a heavier harness with heavier relays.

[Fowlhunter]

according to that they supply the pin for the PCM. so I dont need to send you one


Who is programing your PCM to run that pin?

I thought the pin came wired into the harness, I don't think so? 

Nelson Performance is, I can buy a PCM that is programed to run the fans from them for $35 according to email conversations I have with Allen. Once I install the PCM I purchase from them I send them my old one.

[Fowlhunter]

that should save you needing to add pins then......Make sure you tell them you got the Tahoe fans, this is a 2 fan setup as opposed to the LS1 single fan setup. There is a difference as there should be two pins instead of just one. Also on that note. The Tahoe fans draw more amps so it should be a heavier harness with heavier relays.

I thought so but I was getting confused.  I thought I read pin slot 42 & 33 but could be wrong?  When Allen and I spoke he said all the harness were the same, I'm pretty sure their harness comes with 3 40A relays?  I'm going to try to attach the link were you can look at the harness, let me know what you think.

http://www.nelsonperformance.com/products.htm#fans

Thanks Man!

[Main One]

I thought so but I was getting confused.  I thought I read pin slot 42 & 33 but could be wrong?  When Allen and I spoke he said all the harness were the same, I'm pretty sure their harness comes with 3 40A relays?  I'm going to try to attach the link were you can look at the harness, let me know what you think.

http://www.nelsonperformance.com/products.htm#fans

Thanks Man!

From an earlier FlaBouy post, it seems as if Nelson has changed their harness configuration for folks running the truck fans since I bought mine from him.

I'm running the truck fans with I guess the older Nelson harness configuration which has 30 amp relays.  I think I've been running it for about 2 years now, roughly 60,000 miles.  I have had to replace one of the relays.  The new one has been surviving quite a while now.

[Fowlhunter]

From an earlier FlaBouy post, it seems as if Nelson has changed their harness configuration for folks running the truck fans since I bought mine from him.

I'm running the truck fans with I guess the older Nelson harness configuration which has 30 amp relays.  I think I've been running it for about 2 years now, roughly 60,000 miles.  I have had to replace one of the relays.  The new one has been surviving quite a while now.

I'm pretty sure Allen told me they are using 40A relays??  Did your harness come with a pinned wire (slot 42) for the PCM?  According to the picture and the installation instructions it does?

Thanks 

[Fowlhunter]

I'm pretty sure Allen told me they are using 40A relays??  Did your harness come with a pinned wire (slot 42) for the PCM?  According to the picture and the installation instructions it does?

Thanks 

I forgot to ask, Are you running a 145A alternator, if so where did you purchase it or did you have one built like OBB did?  My girlfriends 05 WBH is using the 145A but I'm told it's not a plug & play?  The brackets are the same but her belt is a little longer, the plug may even be different?  I have not pulled the plugs to see if they match.

[oHIobellboy]

I thought so but I was getting confused.  I thought I read pin slot 42 & 33 but could be wrong?  When Allen and I spoke he said all the harness were the same, I'm pretty sure their harness comes with 3 40A relays?  I'm going to try to attach the link were you can look at the harness, let me know what you think.

http://www.nelsonperformance.com/products.htm#fans

Thanks Man!

I'm not sure on the 02's as far as the pins setup. I know on the later models the set up for 2 fans requires 2 pins to be turned on, hence the 42 and 33 pins that I've done.
Looking at the pix in the link you provided it looks like the ecm pin is on there. Just have to put it in the correct spot on the ecm

I forgot to ask, Are you running a 145A alternator, if so where did you purchase it or did you have one built like OBB did?  My girlfriends 05 WBH is using the 145A but I'm told it's not a plug & play?  The brackets are the same but her belt is a little longer, the plug may even be different?  I have not pulled the plugs to see if they match.

The 05 alternator will not go onto an earlier year. The plugs and wiring are different. If you're not running extra power accessories like compressors or stereos you will probably not experience any issues with the stock alternator once the fans are up to speed. The only time you may notice a dimming of the lights or such is when the fans initially turn on, that's when they have the big amp draw. When I took my avy to Ohio Generators to see what I needed I only pulled 80 amps and that was with EVERYTHING running. My fans are set to come on at two different temps so they should not exceed my alternator output even if everything is running when they turn on.

[Fowlhunter]

I'm not sure on the 02's as far as the pins setup. I know on the later models the set up for 2 fans requires 2 pins to be turned on, hence the 42 and 33 pins that I've done.
Looking at the pix in the link you provided it looks like the ecm pin is on there. Just have to put it in the correct spot on the ecm
The 05 alternator will not go onto an earlier year. The plugs and wiring are different. If you're not running extra power accessories like compressors or stereos you will probably not experience any issues with the stock alternator once the fans are up to speed. The only time you may notice a dimming of the lights or such is when the fans initially turn on, that's when they have the big amp draw. When I took my avy to Ohio Generators to see what I needed I only pulled 80 amps and that was with EVERYTHING running. My fans are set to come on at two different temps so they should not exceed my alternator output even if everything is running when they turn on.

I thought you told me they were not plug and play, good to know. I'm not running any extras at this time but maybe someday??  I would like to upgrade from the 105A anyway but I want to find a number for one so I can go to any store and pick it up, I don't want anything special.  80 amps, that's not bad.  You are the Man!!!    Dude!!!!!

[Fowlhunter]

I'm not sure on the 02's as far as the pins setup. I know on the later models the set up for 2 fans requires 2 pins to be turned on, hence the 42 and 33 pins that I've done.
Looking at the pix in the link you provided it looks like the ecm pin is on there. Just have to put it in the correct spot on the ecm

I should probably contact Allen again and ask him if the 02 requires 1 or 2 pins, It looks like the harness only has 1 pin.

[oHIobellboy]

I should probably contact Allen again and ask him if the 02 requires 1 or 2 pins, It looks like the harness only has 1 pin.

There is a way for the fans to run seperately, I had 06MonteSS copy the fan settings from WB's05 into my tune he did for me.

Gotta run, will catch up more later.

[Main One]

I'm pretty sure Allen told me they are using 40A relays??  Did your harness come with a pinned wire (slot 42) for the PCM?  According to the picture and the installation instructions it does?

Thanks 

Yes, the instructions had me insert a pin, slot 42 sounds familiar.

[Main One]

I forgot to ask, Are you running a 145A alternator, if so where did you purchase it or did you have one built like OBB did?  My girlfriends 05 WBH is using the 145A but I'm told it's not a plug & play?  The brackets are the same but her belt is a little longer, the plug may even be different?  I have not pulled the plugs to see if they match.

I'm running a 145A alternator off of an 05 Suburban.  I assume it is no different than that from an 05 truck or other AV.  The plugs were the same.  It did need a slightly longer belt.  I recommend a Gatorback as the other one I used would give me an ocassional squeal.

The alternator on my wife's 99 suburban with a 2nd-generation 5.7 liter (350) engine was going bad.  It is now running with the AV's original alternator, even though my mechanic didn't think it would work.  Those plugs were the same too.

I got a great deal on my alternator.  $45 on ebay, including shipping and handling.  The seller indicated very low miles as the suburban was a commercial vehicle getting a fair amount of power-hogging aftermarket equipment installed.  They cited approximately 100 miles on it.  When I saw the alternator, I believed them - it looked brand new.

[Main One]

I'm not sure on the 02's as far as the pins setup. I know on the later models the set up for 2 fans requires 2 pins to be turned on, hence the 42 and 33 pins that I've done.

On my 03, and KY_Bob's 02, we just installed I believe one pin on the PCM.  This line gets triggered by the computer when the coolant temp reaches the temperatures set by our computer tuning (for us, via HPTuners).

Our harnesses were also connected to a wire using a tap that would drive the relays indicating the AC compressor was running.  We therefore in our setup have 4 modes of operation:

1.  Off - no AC compressor, low coolant temp
2.  Both fans low speed - no AC compressor, high coolant temp
3.  Passenger side fan on high, other off - AC compressor on, low coolant temp
4.  Both fans high speed - AC compressor on, high coolant temp.

[Alaska_AV]

the 2002 pcm only has one pin to turn on the fans #42  the second wire is taged to the AC for the high setting


In later years of the Av pcm has 2 pins to run fans  High and low
/ Im not sure the year it changed

[Fowlhunter]

I'm running a 145A alternator off of an 05 Suburban.  I assume it is no different than that from an 05 truck or other AV.  The plugs were the same.  It did need a slightly longer belt.  I recommend a Gatorback as the other one I used would give me an ocassional squeal.

The alternator on my wife's 99 suburban with a 2nd-generation 5.7 liter (350) engine was going bad.  It is now running with the AV's original alternator, even though my mechanic didn't think it would work.  Those plugs were the same too.

I got a great deal on my alternator.  $45 on ebay, including shipping and handling.  The seller indicated very low miles as the suburban was a commercial vehicle getting a fair amount of power-hogging aftermarket equipment installed.  They cited approximately 100 miles on it.  When I saw the alternator, I believed them - it looked brand new.

Good to know, I think the 02 (mine) alternator has a 4 pin connector and my girlfriends 05 has a 2 pin connector?  When I say 2 & 4 pins, the alternator itself has these pins in the connector, does that sound right??

[Main One]

Good to know, I think the 02 (mine) alternator has a 4 pin connector and my girlfriends 05 has a 2 pin connector?  When I say 2 & 4 pins, the alternator itself has these pins in the connector, does that sound right??

I think all of mine have 4 pins.

[oHIobellboy]

Mine are in and working     

[Main One]

Scratch that mod off the to-do list!

[WB]

Mine are in and working     

       

[Alaska_AV]

Ya baby!!!!!!

do you have to wait till summer to have them come on also?

[oHIobellboy]

Ya baby!!!!!!

do you have to wait till summer to have them come on also?

LOL,,,nah, it got in the mid 50's here yesterday, I had to drive it a little to get them on but they work. 

[WB]

Ya baby!!!!!!

do you have to wait till summer to have them come on also?

I bet YOURS rarely come on in the great white north!    

[Fowlhunter]

Mine are in and working     

Nice job Man!!!!  I love it when a mod is complete!!!  All your hard work paid off!!!

                      

[Alaska_AV]

I bet YOURS rarely come on in the great white north!    

I want to mod them now

see If they make any juice ar 70mph. maybe charge batterys for wallmart or somthing

[Fowlhunter]

I want to mod them now

see If they make any juice ar 70mph. maybe charge batterys for wallmart or somthing

I can't wait to get mine installed!!!!!

[WB]

I want to mod them now

see If they make any juice ar 70mph. maybe charge batterys for wallmart or somthing

regenerative fans ....great idea!   

[oHIobellboy]

I guess I should post up the pix and all.

And here goes the pix and intruction thread.

PARTS NEEDED
Fans : I used 05 Tahoe fans which are the same as what's in the newer avy's. A single LS1 fan will also work and there are a few aftermarket companys that also make them
Harness: I got a GM harness Part number 15912597
I also upgraded my alternator to a 145 amp from Ohio Generator
I also had to get pins to add to the ecm from a junkyard
06MonteSS did a custom tune for my Predator to controll the fans through the ecm.

Here goes:
The Fans


The Harness
I can't believe I didn't get a pix of the harness... :BangHead:Here's a gm drawing

I had to take the fan relays and wires apart from the wires for the lights.

The ECM end of it
junk harness from a junkyard

To get a pin out to add to your ecm you have to take it apart, note the green wire I've separated from the old harness. You will need 2 pins (one for pin 42 in the blue harness for the low speed cooling relay and one for pin 33 in the green harness for the high speed cooling relay


I added wire to the pins to reach the fuse box


Location of the ecm on the avy, you can see the pigtails of the longer wire I added.

with the cover pulled back in yellow

The ecm harness and the pinning process




NOW THE FUN BEGAN:
stock fan pix


fan shroud pins , they're the 2 part plastic ones like the one on top of the radiator cover


top 1/2 of the shroud gone


My poor mans spanner wrench to get the old fan off,  use a big enough cresent wrench and a hammer to LIGHTLY tap the drivers side of the wrench. Notice the way the wrench in positioned on the fan nut. This will loosen that nut up very easily




Viola, no more fan


when it's done, I still had to put the intake back on it at this point.

I had to run to the hardware store and get a couple of bolts and washers to hold the top of the fans in. The bottom sits right in the groove where the old one went and the side clips on the radiator.

The wiring

You have to remove the fender brace to get the whole fuse box off


These pix show the fuse box with the cover off and then with the relay box in the factory position to the right side




This pix shows where I attached the + for the fans (green) and where I tied the ecm wires into the harness wires. I found a plug on the light harness (yellow) and used it to plug into the ecm pins into the fan harness after soldering and heat shrinking the ecm pigtails


I think that's it.

[Fowlhunter]

Dang Man, very nice!!!!     I think I can even follow that, I hope?!?!   

I sent Alaska_Av a PM and copied you.  What model and year truck did your harness come out of? 

Nice job OBB!!!  Now get the leaking power steering box repaired!! 

[oHIobellboy]

Dang Man, very nice!!!!     I think I can even follow that, I hope?!?!  

I sent Alaska_Av a PM and copied you.  What model and year truck did your harness come out of? 

Nice job OBB!!!  Now get the leaking power steering box repaired!! 

The harness came from GM.   The leaking ps box should be under warranty so I'm compiling a list for my mechanic to take care of all at once.

[Fowlhunter]

The harness came from GM.   The leaking ps box should be under warranty so I'm compiling a list for my mechanic to take care of all at once.

Nice job on the fans!!!  I was just yanking your chain on the power steering box!

[Fowlhunter]

OK, I was off today so I did a little more research on the alternator I need (145a) for the efans.  By the way OBB was correct, he told me he didn't think the 145a alternator that's in my girlfriends 05 Av w/efans was a plug-n-play in my 02.     The alternator (105a) for the 02 (mine) has a 4-pin plug and the alternator (145a) for the 05 (my girlfriends) has a 2-pin plug.  It's not that I didn't believe you Mike but I had to look for myself. The dealer actually had all three (105a 4-pin for the 02, 145a 2-pin for the 05, & the 145a 4-pin to replace the 105A) in stock for me to compare!!  I didn't get the price because I probably wont buy it from them.
GM #19151921, 145a alternator, 4-pin. I'm not sure but I think the belt will need to be longer as well? The parts guy really couldn't help much with that.  He was actually a little ticked off as it was. 

[Fowlhunter]

As you all know I'm in the process of gathering all the parts needed to do my 05+ GM efan install!!  The part I'm currently looking for is the rubber grommet (upper insulator) that goes in the slot (on the fans) where the fans are bolted to the core support.  This appears to be the same rubber grommet that is used to connect the radiator to the core support? The dealer tells me this grommet doesn't have a GM # and is not sold, it's actually part of the efans and part of the radiator.  I don't think the efans I purchased has this grommet but I'll need to look again to be sure??? 
Who has installed the 05 GM efans and what have you used?

Thanks, FH.

[Main One]

I don't recall a grommet.  I was surprised at how little hardware was needed to attached the efan to my radiator.  All I can recall is a few screws at the top of the radiator support, but it has been a few years now.  Those screws were used to attach the shroud for the stock fan - I just had to take them out to get the shroud off, and then reuse them with the efans.

[Fowlhunter]

As you all know I'm in the process of gathering all the parts needed to do my 05+ GM efan install!!  The part I'm currently looking for is the rubber grommet (upper insulator) that goes in the slot (on the fans) where the fans are bolted to the core support.  This appears to be the same rubber grommet that is used to connect the radiator to the core support? The dealer tells me this grommet doesn't have a GM # and is not sold, it's actually part of the efans and part of the radiator.  I don't think the efans I purchased has this grommet but I'll need to look again to be sure??? 
Who has installed the 05 GM efans and what have you used?

Thanks, FH.

Nevermind, I just looked at the efan assembly again and it does have the rubber grommet (upper insulator) installed!!!!!!!!   

[Fowlhunter]

OK, my efan mod is installed!!!!!!  Not complete as I still need to mount the three relays from the NP harness, I just have them ty wrapped to the power steering hose so they don't wiggle around.  I also need to find two harness (wire loom) fasteners so I can mount the lower portion of the harness to the fans, I currently have the one ty wrapped as well.  MyBigToy told me about a place to find them but right now I can't remember what it was.     I was off Friday to do the mod, I started around 9:30-9:45 central time and finished around 5:00ish?  This is a very sweet mod!!!!!!!   
The only pics I took were what it looked like before I started (with the old components in place) and after the mod was done.  I hope to get the pics posted as soon as I can. 
Many, many, many Thanks go out to Mike (OBB)!!!!!!!!  I pretty much had him on retainer by cell all day Friday!!  Thanks again Mike, I couldn't have done it without your help!!!  I also want to Thank Joe (MyBigToy), he hooked up his predator for me on Saturday and was able to determine the error code (Crank Shaft Relearn), I may be able to live with the service engine soon light for a short time???
I also want to Thank everyone else here at CAC for all their input, opinions, pics, etc.................................!!!!!!!!!!

 

Fowlhunter

[Main One]

Congrats on the install.

By the way, I never did get around to mounting my relays on anything - they're just sort of hanging there in space.  Been that way for about 3 years now and counting!

[Fowlhunter]

Congrats on the install.

By the way, I never did get around to mounting my relays on anything - they're just sort of hanging there in space.  Been that way for about 3 years now and counting!

Thanks Man!!!  I'm pretty anal retentive, ask Joe (MyBigToy) so I hope that helps me get them mounted?  Finding the time between the kids and baseball for my son will be an issue, I needed to take off a day just to do the install.  Wish I would have done this sooner. 

[Main One]

Thanks Man!!!  I'm pretty anal retentive, ask Joe (MyBigToy) so I hope that helps me get them mounted?  Finding the time between the kids and baseball for my son will be an issue, I needed to take off a day just to do the install.  Wish I would have done this sooner. 

I have found that one of the best cures for anal retentiveness is having more to do than time to do it in!

[MyBigToy]

I have found that one of the best cures for anal retentiveness is having more to do than time to do it in!

No, that just means you keep getting further and further behind. My wife has given up on adding things to the honey-do list since she knows I won't get to her stuff until I get my priority stuff done first. I think I've finally got her trained after almost 24 years of marriage! 

[Main One]

No, that just means you keep getting further and further behind. My wife has given up on adding things to the honey-do list since she knows I won't get to her stuff until I get my priority stuff done first. I think I've finally got her trained after almost 24 years of marriage! 

I guess you are assuming that getting behind is an option!

[oHIobellboy]

No, that just means you keep getting further and further behind. My wife has given up on adding things to the honey-do list since she knows I won't get to her stuff until I get my priority stuff done first. I think I've finally got her trained after almost 24 years of marriage! 

 




Hey FH,,,those "harness fasteners" you need. describe them to me. If it's what I'm thinking I've got half a box full from my two harnesses I bought.

[Fowlhunter]

They are round with a stud on the back side, they also unsnap which allows for the loom to lay in then close to hold it in place.  Take a look at the loom of wires I tapped into (between the red hot box where the alternator cable connects into and the alternator mount) for the A/C trigger, there is a grey colored loom bracket/fastener.  I need a few like that but probably for a 1" diameter loom???

[Fowlhunter]

OK, I did my efan mod ( I know, pics will be on the way sometime) and the Nelson harness I used has three relays.  I want to be proactive and find a spare relay and stash it in the glove box just in case I need a spare but I searched the internet and couldn't find one with the same number, Is there a Bosch relay maybe the same but with a different number that I could use??

The number and description on all three relays in the Nelson harness are:
#Y41A-1C-12DSM
Desc: NO: 40A/NC: 30A 12VDC

Like I said I searched but couldn't find it.  I may give Nelson a call or drop them an email to see if they can provide me with the folks they buy them from.

Thank, FH

[Main One]

I suggest you unplug one of them and take it into an auto parts store and tell them you are looking for a replacement for it.

[oHIobellboy]

They are round with a stud on the back side, they also unsnap which allows for the loom to lay in then close to hold it in place.  Take a look at the loom of wires I tapped into (between the red hot box where the alternator cable connects into and the alternator mount) for the A/C trigger, there is a grey colored loom bracket/fastener.  I need a few like that but probably for a 1" diameter loom???

I forgot about these. I have what you need if you don't get them before you pass through.

[ChevyGuyNC]

I forgot about these. I have what you need if you don't get them before you pass through.

Is there anything you don't have?? 

Oh yeah, I forgot...
























A Bermuda Blue Av  

[oHIobellboy]

Is there anything you don't have?? 

Oh yeah, I forgot...

A Bermuda Blue Av  

Watch it there pal    



 

[Fowlhunter]

I forgot about these. I have what you need if you don't get them before you pass through.

I've been doing some digging on these wire loom routing clips, the size of the loom I'm looking to attach is about 11/16" - 3/4" OD.  I've been talking with my friend at the dealer but have not yet purchased anything.

[Fowlhunter]

I suggest you unplug one of them and take it into an auto parts store and tell them you are looking for a replacement for it.

That might be the easiest way to go about it? 
Thanks man!! 

[Alaska_AV]

I've been doing some digging on these wire loom routing clips, the size of the loom I'm looking to attach is about 11/16" - 3/4" OD.  I've been talking with my friend at the dealer but have not yet purchased anything.

 

http://cgi.ebay.com/ebaymotors/25-Wire-Loom-Routing-Clips-1-2-I-D-11-16-O-D_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem1c0752fe45QQitemZ120381963845QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[oHIobellboy]

 

http://cgi.ebay.com/ebaymotors/25-Wire-Loom-Routing-Clips-1-2-I-D-11-16-O-D_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem1c0752fe45QQitemZ120381963845QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

nice find AA....I gave him a few when he went through Ohio last month. I have a handful leftover from the 2 harnesses I bought for my project.

[Fowlhunter]

 

http://cgi.ebay.com/ebaymotors/25-Wire-Loom-Routing-Clips-1-2-I-D-11-16-O-D_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem1c0752fe45QQitemZ120381963845QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Thanks AA but like OBB said, I picked up a few from him when I was in Ohio!!!!!!
Thanks again Mike, these work well!!!!!!!!!!!!!!!!!! 

[bluedevil]

OK, I did my efan mod ( I know, pics will be on the way sometime) and the Nelson harness I used has three relays.  I want to be proactive and find a spare relay and stash it in the glove box just in case I need a spare but I searched the internet and couldn't find one with the same number, Is there a Bosch relay maybe the same but with a different number that I could use??

The number and description on all three relays in the Nelson harness are:
#Y41A-1C-12DSM
Desc: NO: 40A/NC: 30A 12VDC

Like I said I searched but couldn't find it.  I may give Nelson a call or drop them an email to see if they can provide me with the folks they buy them from.

Thank, FH

FH, i just got contacted via email by a guest who was reading your post.

The relays he is looking for are sold at Parts Express as their P/N 330-079 ($2.89ea)
parts-express.com

...and no,he doesnt own an Avalanche but a 96 Impala SS

[Main One]

Get sealed relays.  I put on a relay earlier this summer that wasn't sealed (had a cover that would snap off and on) and it has twice stuck in the on position.  Would run down the battery pretty quickly if I hadn't caught it.  The last time was when I pulled in at Bratfest.  Luckily I had a replacement with me but hadn't installed it yet.  It was my first Bratfest "mod".

[Fowlhunter]

FH, i just got contacted via email by a guest who was reading your post.

...and no,he doesnt own an Avalanche but a 96 Impala SS

Thanks Mick,     I didn't think I was going to get a response on this one?  I guess if I would have posted pics maybe someone would have replied?

Thanks again!!!!!