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