Electrical Issues in 2001 gmc sierra need help

[takoda67]

I

 

My son has a 2001 GMC Sierra std cab short bed with a 5.3 L

 

We are having issues with the fog lights, DRL, and A/C.

 

I have checked all the fuses plus replaced with new just to be sure, we have also replaced the relays for all also. If I pull the relays and use a jumper wire across the terminals I can get them all to work but when I re-install the relays either new or old nothing works. I have replaced the head light switch and this did not fix the problem with the DRL either.

 

Any thoughts and ideas would be greatly appreciated. Thanks

[jhm]

Could be something to do with the PCM. I would get a tech to scan it.

[oldscsc]

What is the issue with each system?

 

We need specifics to point you in the right direction.

[takoda67]

We have installed new factory replacement fog lights, all fuses are good the only thing I see is the push button for the fog lights has a small light next to it and nothing happens when the button is depressed or pushed.

 

The DRL lights stopped working two days ago, I have checked the fuses and installed a new head light switch and they do not work. All other lights work fine ie: turn, park, tail, head.

 

 

the AC is the same as the others, I can pull the relay and jump across terminals and they all work if I do this.

[jhm]

He said the relays don't work but when he uses a jumper across the pins everything works. The relay sockets getting ground etc from ECM. I think that is where the problem is. A scan would tell.