Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Have you replaced the low pressure switch?
That is where your ground comes from controlled by the pcm. If you jump ground from the low pressure switch will it run?
Okay disconnect the connector and jump to the black wire. If that does not work tell me what you are grounding to the compressor. It could be shorted at the splice before the compressor.
If you disconnect the low pressure switch you should have no problem backprobing and bringing it to ground. The low side switch goes directly to a splice than to the compressor. Earlier you stated if you jumped ground it would work. SO this leaves the low pressure switch the pcm or the wires from the pcm low pressure switch to the compressor.
It should not effect the ac. Can you tell me what spot you jump to get it to engage.
Did you check the CIGAR fuse?
Does the scan tool power up when you turn it on?
I think you have a bad ecu to be honest. Starting to point that way to me. Did you jump 12v to the ecu?
You said you jumped one of the wires that go to the ecu for the ac and it went on. Just wondering. But yeah if you get a used one that matches your vehicle options than no you will not need any programming.
Just the one. All of the wires going to the AC should be a 5v ref voltage 12v would fry the ecu..