Electric fan install into an HD truck

tbyrne · June 13, 2003

I installed a set of Flex-a-lite 290 fans into my 2002 Silverado HD with the 8.1 motor. This kit comes with universal brackets so you pretty much have to come up with a way to mount the radiator.

I bent two of the brackets so they could be mounted to the top of the radiator support and then hang the fans from there.

After that I used some plastic strips from B+M to attach the fans to the radiator. I don't remember the part # for these but I can get that tomorrow.

Trucks with the Allison transmission have a seperate computer to control the tranny. This is mounted on the driver's side of the fan shroud. This will press up tight against the fans. I tried a few different locations but it was starting to become in PITA so I figured the stock location would be the best choice. I tried out part of the cover so it would go around the bracket and then mounted it leaving the two 10mm bolts a little loose. I also tied the bottom of the plastic cover back away from the fans with some straps. I might come up with a better way to do this but it's working pretty good.

While I had everything apart I also installed a ported throttlebody and throttlebody spacer. Did some driving that might and found that I gained close to 2 MPG. This truck gets thirsty with some of the mods and big tires so these were worthwild additions.

If anyone else is thinking about using these here are a few quick notes that will help your install. The fan controller needs to be connected to a wire that is hot when the truck is keyed on and cold when it is off. If you take the cover off of the fuse box under the hood and then lift up the cover that has the fuses in it you see 6 different sections. I used a wire in section 1 ( top left hand corner). Count two wires over from the right and 3 down. You will find 2 wires here. I used the purple one on the right. You also need to tap into the activation wire that goes to the clutch compressor for the AC. There are two wires there. I used the green one. These tips should help you get through the install in a couple of hours.

The Suburban will be getting a set of these next week.

Tom

2002 8.1 Silverado HD - Comp Cam, TOGs headers, Volant induction, Direct Hits ignition, 6" lift 18" wheels/tires + more

2002 8.1 Suburban -Intercooled Whipple supercharger, TOGs headers, Volant induction, 22" wheels/tires + more - 14.54 @ 92.43

www.tbyrnemotorsports.com

8.1 HD GMC · June 13, 2003

Very cool, what do the fans cost?

What is the expected gain in HP and MPG?

8100HD · June 13, 2003

Tom, shoot me a pm, I'm looking at getting fans, TBS, ported TB, and cam. Looking for price and availability.

tbyrne · June 13, 2003

8.1 HD GMC: We carry the 290 fans for $449.99. I saw close to a 2 MPG gain from these and the other two mods. Gains are usually rated at around 15hp from the fans.

8100HD: I have my board PMs turned off (to many boards to keep track of that mail). Our last set of 290 fans went out yesterday. I should be seeing another shipment in a few weeks. More ported throttlebodys should be available next week and the cam is a special order item. They usually take about 7-10 days.

Tom