not getting power to ac compressor. 1988 GMC 3500

Asked by Jun 14, 2016 at 07:00 PM about the 1988 GMC Sierra C/K 3500

Question type: Maintenance & Repair

clutch will engage when jumped, 2 prong plug that connects to compressor has no power. Any ideas? Thanks

4 Answers


Pressure switch on the accumulator tank is probably keeping It shut down is the AC cold when jumped? Check R134a high and low side Psi readings

I did not leave it jumped at the low pressure switch very long, just long enough to see if compressor would kick on. How long can I keep it jumped at the switch? Thanks

I jumped the low pressure switch and added a can of R134, It is leaking ant connection going into firewall from accumulator tank. Will there be an o-ring and will I need to have a vacuum pulled in order to charge? Thank you


Pay $85-100 and have it evacuated, checked for leaks 30mm of vacuum ...and filled with the correct oil PAG,# and amount. Then filled to the correct weight ONLY proper way, of refrigerant 134A. That's what I suggest..

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