Troubleshoot A/C

TODD STEWART

MEMBER
2006 CHEVROLET SILVERADO
4.8L
V8
4WD
AUTOMATIC
110,000 MILES

My A/C worked for about fifteen minutes and then would not come back on the rest of the day. This happened each time I started my truck, when I started using it this spring, this happened for about four days. Now it will not come back on at all. I stopped at the local shop to get it recharged, the mechanic said it was charged properly and that it was something else. He was able to make it work by jumping out the relay, compressor kicked in and it blows ice cold. He is not able to get my truck back in for about two to three weeks. Is there anything I can test and change without having to remove the refrigerant. Wiring diagram would help, cheers.

Thursday, May 24th, 2018 AT 4:51 PM

1 Reply

ASEMASTER6371

MECHANIC
52,796 POSTS

Good afternoon.

You need to check for power to the relay control side. He jumped 30 and 87 to get the compressor to come on.

You need power to 86. It is the control side of the relay. It is power by the fuse block. Check the fuse for power on both sides of the fuse and then to the relay. The PCM grounds the control side to send power to the compressor. It grounds it when it gets the correct readings from the pressure sensors. If they are not working correctly, it will not ground the relay.

Roy

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