🔌 Efficient GM Dual Electric Fan Upgrade Wiring Harness for Enhanced Cooling - 1999–2006 ECU Control Kit Review

Relays, fuse blocks, contacts were ok. The only criticism is the ground cable. Too small to go anywhere! So don't forget to lengthen the bottom to make it effective.

Great quality harness but as others have said you will need to add a foot of 8ga wire to the grounded case to the fan connections. If you buy you will see that it works great and is a clean setup.

Don't buy this wire harness less than 90 days ago and my truck almost burned the wiring from the relay to the 8g fans but the power wire that runs the 12 g lists fans insufficient to run fans they used on on-site factory fans in 2005. I've had to rewire my fans roadside to come and go home, only 90 day warranty, wasted money and time building a custom wiring harness. currently

Easy to install but no instructions included. The ground wires were too short, they had to be spliced together and a good foot of 8ga wire added to the negative terminal. This kit is for 2003-2004 models only. Both wires go to the ECU contacts. The white wire you see in the picture goes to the green side of the ECU on pin #33 and the greenish wire goes to the blue side of the ECU connector on pin #42. You will need hptuners to get them working. 4/5

The cables were connected incorrectly. They had a task, and that was to develop a wiring harness that would allow the fan to run at low speed when the engine was running and at high speed when it reached a certain temperature. But someone did a terrible job with the wiring harness resulting in a fan idling resulting in a leak and terrible air conditioning. Had to get this crap off my truck before it killed my AC clutch or worse...

Don't buy this wire harness less than 90 days old and mine nearly burned my truck, relay wiring to 8g fans but 12g fan power wires not enough to run fans used in 2005 suburban factory fans, had to rewire my fans roadside to come and go home, only 90 day warranty, now I will spend the money and time to get a custom one build wiring harness.

Fairly easy kit. Use silicone spray to push the pins through. Use a lot. Green goes to 42 on the blue ECM field. White rises to 33 on the ECM red box. I installed a relay on the side cover of the ECU. I have a 2001 Sierra, 99-2002, you may have a wire on number 33, although CAREFULLY push it. The HP tuner helps you turn on the fans. I would upgrade a 34" heatsink and fan. All pre 2012 fan headers are the same. The ground wire is too short and won't fit. Get the extra foot of wire you need.

First, the quality of the wire on this wiring harness is rubbish. Also, most wires are too short to reach their intended locations. After a very cumbersome installation, I programmed the ECU for fans, but only one of the fans came on. I checked the fans and knew the computer had been repaired, leaving the wiring harness behind. Then, as I was driving my Suburban back to the house, a fan shut off causing the car to overheat and the AC clutch to burn out. Needless to say I was unhappy. I ended up

I have a 2002 Avalanche. I fixed this by using others' comments as instructions. On my truck, the cables go the other way. The white wire goes to pin 42 and the green wire goes to pin 33. There was already a wire on pin 33, you need to remove that wire (the AC recirculation wire you don't need with the fans) and insert the wire from the kit. Then have someone who knows what they're doing with hptuners tell the computer they have efans. They work as they should, both fans turning on at low and…