I purchased and installed a PCMforless e-fan harness for LS1 fans. Its on a 2002 Silverado 4.8L and once installed, one fan stays on all the time even after the ignition is off. I noticed that one pin was already being used in the PCM connector so I just spliced into that one. The other pin went into an empty spot. I know it went in all the way and all but I dont know why they are staying one.
What sucks is that pcmforless didn't even include instructions for the tune part of it.
Any help?

 

I know on BlakBears harness the 2000-2002 trucks use 1 wire to the PCM and another goes to the AC wire or something odd like that. On a 2002, with the dual pin, you would need to reconfigure the PCM to have red pin 33 function for fan control rather than A/C, System / AC is where that option is... Table G0106 in EFI Live.

 

Yeah you can also take the PCM connector apart, actually take the red piece off and can pop out the 33 wire pin out and slip in the one for the harness so you dont have to splice any wires. I just installed a dual pin setup on my truck today with a blackbear harness and 07 efans and its working great after I changed table G0106.

 

ok but I disconnected the pin going to the AC and it still stayed on. It seems like the one from pin 42 is always grounded.

 

Im using HPTuners
I see a drop down box with: 2 Fans, Aux Fans, or No Fans
Then the on/off temps for 1 and 2, ac pressure on/of, delay, min time, and ac fans disable speed. Also Ignition off run time and temp.

on the AC tab it shows: "AC recirculation" or "Fan #2"

 

So the Pin 33 from the original GM harness isnt needed?

 

You set the fan type to Series Parallel and G0106 to Fan #2 control and red 33 becomes the secondary fan trigger instead of the hvac auto-recirculation.
Not sure about that...

 

Maybe your PCM can't be configured to run e-fans like I am thinking. Maybe that's why you dont have series parallel fans as an option and that's why one stays on.

 

Yes you have to use that spot on the PCM connector red connector pin 33. I was simply saying instead of splicing into that wire you can actually remove the wire and the metal pin connected to it from the connector and slip the efan harness wire with the metal pcm pin into that slot so its a factory install without any splicing. you ahve to remove the clear red plastic cover to get to the plastic tab that holds the metal end of the pcm pins in.

 

My truck is an 01 and Ive got all the options youve talked about and configured my fans just like youre telling him so there shouldnt be any reason why he cant do the same unless its a difference in hpt and efi.