I just installed my fans, and the one that is supposed to be controlled by the PCM will not come on.

I've triple checked that it's in the correct location and installed correctly, and i've swapped fan plugs around to make sure the motor is good, and it is.

Shouldn't the blue wire (from pin 42 to relay) go to ground to start the fan? Mine is hot even w/ the truck off

?????

 

Yessir, pin 42 should ground when the engine reaches the temp that your fans are set at...I can't remember if it's the blue or red pcm connector though. There shouldn't be any voltage there

 

That's what i thought. It's a blue wire, the other is green and it's the a/c pwr trigger.

Maybe my PCM programming is wrong. Is it possible that he accidently set it up to go + at the desired temp., instead of go -??

 

I don't think there is an option to change the output of the pin. At least there isn't with HP tuners. You can only change when it is grounded or not by setting the temp for the fans in the program.

 

oh ok.

well what in the world would cause it to be + then??

i'm on the pcm closest to the engine, and on pin 42, i've double checked it 20 times now. i know i'm in the right spot, but not sure what is going on.

 

When you are testing the voltage for pin 42 of the blue connector I would unplug all the relays. I am suspecting you have another wire that is meant to be to a ground on a positve source and that would be where the + voltage is coming from....

Please don't ask why I am coming to this conclusion. It will make me feel stupid.

 

Ok i got it! I'm an electrical idiot! Everything was working fine, i just tested it wrong, and didn't wait long enough for it to come on.

thanks for the help though!

 

Good to hear. The occasional moment of stupidity happens to the best of us...

 

make sure you have the pin pushed in all the way. they are tricky.

 

Good to hear it is working now man.