Problem with LS1 electric fans and harness

[GMCtrk]

I installed LS1 electric fans and am using a blackbear harness which I believe is a copy of the Nelson harness. Anyways, I got it hooked up and all I am getting is the passenger side fan running on high all the time? The driver side fan never comes on. I verified that the pin is correctly installed in the harness. I spliced the green wire into the solid green AC trigger wire in the loom next to the junction box. My A/C works as it should after the swap. I switched the connector from the passenger fan to the driver's side fan and it came on high. So I know that my fans are good. Any thoughts? Thanks

[LARRY01Z28]

ive never seen that problem. maybe contact who you got the harness from. maybe its wired wrong? or maybe its in the tuning??

[GMCtrk]

I set the tune to series parallel fans, also tried aux fan and that did nothing. I'm not aware of anything else left to do in the tune. It seems pretty simple. I did contact blackbear and they told me it's a common problem when the pin 42 is not seated all the way. I confirmed today it is seated properly.

[LARRY01Z28]

heck i dont know. ive used 3 sets of nelson fan harness and never once had a problem??

[RedHeartbeat]

wrong green wire?

[GMCtrk]

I've tossed around that idea. I can't get a straight answer on which wire is the correct one to be tapped. I tapped the solid light green wire. This is the same color as the wire in the harness.

But is still doesn't explain the fact that the driver's side fan is not coming on when I have it programmed to in the tune (192 degrees).

[GasGuzzler]

The Nelson instructions are pretty crappy on which green wire to get but if you access to real info it's not that hard. I went all the way into the underhood fuse panel to repin the output to have two leads...one the where it used to go and one for the fan add.....pulled that wire to a length good enough to get it out from under the panel...put an end on it that made it where I could plug and unplug it at will...added the corresponding plug on the Nelson harness. I can jump the fans to high by pulling the connection apart and adding a jump wire...all wife proof.

[GMCtrk]

so what color was the ac trigger wire?


this is from the nelson instructions:

Located between the junction box and ground mounting point is a group of wires covered by loom. Open up the loom and locate the green wire. (The wire may be light green or have a white stripe as well. If one fan does not come on high speed the incorrect wire was tapped.

This is quite confusing especially since there is both a light green solid wire and a darker green striped wire in the loom

[Chevy366]

In loom 2 green wires , 1 is ground and the other 12v , use the 12v one (key on) .

[GMCtrk]

well, I must have gotten the correct wire then. I was told that this is a common problem when the PCM pin is not pushed in all the way. I checked the pin and it was in. Originally when I was installing the harness I didn't pop the hole in the harness with a pin and I snapped the pin on the efan harness of. So, I have some extra pins and wires laying around from another PCM I had, so I spliced that into my harness. I'm thinking maybe it came loose, or also when I put the pin into the PCM harness I really had to jam it in there hard with a small allen wrench. I'm thinking I may have severed the wire inside of the plastic sheath. So on Saturday I will take that wire out and splice in a new pin and see if that works. If not I will remove the pin, cut the AC trigger wire in the efan harness and then ground the harness pin. If the efans dont both come on low then, I will know there;s something wrong with the harness. I already swapped all of the relays around in all configs and it didn't change anything, so they should be good (I was told to have my symptoms I would need 2 bad relays)