Nelson LS1 Fan Harness Problem

[MKader17]

Ok here is the situation...

*R/L from drivers seat perspective*
AC Off/ Truck not at operating temp (Both Fans Off)
AC On/ Truck not at operating temp (R Fan on High, L Fan off)
AC Off/ Truck at operating temp (Both Fans Off) <--Very Bad
AC Off/ Truck at operating temp (R Fan on High,L Fan off) [The left fan will sometimes seemingly turn on low, seems that it happens some times and not others]

Put connection from R Fan to L Fan and turned on truck and AC and L Fan ran on high. So I know that both fans work. When I received the Kit one relay was damaged so I replaced it with one that I had. Do you know of any way I could test relays to see if they are operating properly? Is there anyway I could have installed the blue wire wrong (it snapped into place when installing seems pretty fool proof) and I am sure I am connected to the right green AC wire (since that is the only thing that is working properly).

Thanks guys, was sitting in the staging lanes tonight and my truck almost over heated on me. Got 2 runs in and the truck only ran 2 tenths faster (This is after a tune LT headers e-fans) very disappointing night.

[BossGMC]

Did you double check it was on pin 42 on the blue Ecm connector, if it is maybe the tune did not go through, because if the a/c part works good, and the engine side doesn''t it has to be the blue wire signal, try splicing the blue wire to battery voltage, first unplug the blue connector from the ECU, when you do that both fans should turn on low...

[MKader17]

Thanks, will check tomorrow morning. if I accidentally put it in the wrong pin hole how do I go about getting it out?

[BossGMC]

Take the blue cover off the connector, then you can release a small lock tab between the pin and connector, and pull on the wire from the back side out...

[GasGuzzler]

Have you had the PCM pin turned on in your tune to make the fans operate with temperature? You have to have that done by a tuner, it won't do it on its own.

[MKader17]

PCM wire is connected in 42 and yes I had Nelson do a retune when I got the e-fans

So it must be Bad relays or a bad tune... I'm sure Nelson didn't mess up on wiring it

[Chevy366]

Do not touch the blue wire to positive voltage it is a ground .
The PCM acts as ground to activate fans .
And not all relays are the same even thought they may have the same pin design .

[GasGuzzler]

Do not touch the blue wire to positive voltage it is a ground .
The PCM acts as ground to activate fans .
And not all relays are the same even thought they may have the same pin design .

+1

[MKader17]

Well I rotated all the Relays around and every time the AC fan still worked as its supposed to, so I suppose the tune didn't go through. I'm sure Nelson is closed today, so i will give them a call tomorrow

[GasGuzzler]

Ooops.

Had a little problem with mine yesterday too. This example was the fault of the installer (*cough*). AC started blowing hot then got the engine coolant hot message....dummy mechanic didn't properly tighten the fan grounds....