Qnbes Upgrade Dual Electric Fan Wiring Harness Fit for GM Truck SUV 1999-2006 ECU Control Replace 7L5533A226T Double Fan Combo Compatible with 05+ GM Truck Plugs

I've been through several of these and I'm not pleased. I wound up eliminating them and just using 2 relays to bring both fans on high. The fuse blocks can't handle it. The relay connectors, (spade connectors), can't either. If it's hot where you live, don't bother trying these even if you move them to a cooler area under your hood. They just can't handle the heat.

Worked properly. The lack of instructions leaves a bit to be desired.

THIS IS A PERFECT WRIIGN HARNESS FOR INSTALLING ELECTRIC FANS ON A 99 TO 2004 CHEVY 5.3 THAT DOESNT HAVE ELECTRIC COOLING FANS.TOOK A WHILE TO FIND THIS ONE, ONLINE THESE GO FOR UP TO 300 BUCKS, THIS IS A PERFECT HARNESS BECAUSE IT IS UNDER 100 DOLLARS AND IS MADE OF HIGH QUALITY MATERIALS.NOTE : IT TOOK A LOT OF TRIAL AND ERROR TO FIGURE OUT THIS RETROFIT.IF YOU WANNA DO THIS TO YOUR VEHICLE, PLEASE READ THE FOLLOWING FOR THE LIST OF OTHER PARTS YOU WILL NEED COOLING FAN ASSEMBLYS FROM A 2005 SILVERADO THIS HARNESS A RADIATOR FROM A 2005 SILVERADO (LARGER SIZE) SOME MORE COOLANT AND A GROUND CABLETHERE ARE TWO GROUNDS ON THIS HARNESS, THE LOWER ONE IS A LITTLE TOO SHORT, BUT CAN BE EXTENDEDTHIS IS A THREE RELAY SYSTEM, SO IT HAS A LOW AND HIGH SPEED ABILITYTHERE ARE TWO PINS FOR THE ECM - A GREEN AND WHITE WIRE.DEPENDING ON YOUR CHEVY, YOUR PCM WILL HAVE TWO MAIN CONNECTORS - BLUE (C1) and Red (C2)OR BLUE AND GREEN.ON THE BLUE YOU WILL NEED TO PIN THE GREEN WIRE TO SLOT #42 ON C1 AND ON THE RED/GREEN YOU NEED TO PIN #33 - ON MY APPLICATION IT WAS A BLUE AND GREEN SETUP.AFTERWARDS THE PCM WILL NEED TO BE TUNED, YOUR ECM ALREADY HAS THE CAPABILITY OF CONTROLLING THE FANS AUTOMATICALLY, BUT NEEDS TO BE TURNED ON. THIS CAN BE DONE WITH HP TUNERS OR OTHER TUNING EQUIPMENT THAT CAN UNLOCK THE PCMAFTER THAT THE FANS WILL OPERATE JUST LIKE ON THE 05 CHEVYSHAVE FUN. ANY QUESTIONS AS FOR THE INSTALL EMAIL ME AT [email protected]

For less then $40, it’s great. The loom on one can plug leg was 6” Too short, and grounds are in sorta weird spots, aka one is short.If people looked at the description, they would see what pcm pins the wires go to.They need to use better heat shrink, the heat shrink slid down on the harness exposing the crimp connections.I used this in a ls swap. So everything was looked over, soldered instead of crimped, and I had to extend almost everythingBut this is because of my situation. Not the harness

The only issue I have with this harness is that the pcm leads are very short. I had to make another lead for the high and low speed wires to make it reach my pcm.