Justin Gibson

Gm techs, got a question if anyone may know a solution.. I have a 2011 Tahoe LTZ that the A/C compressor when I first start the truck will cycle on and off, I assumed it was low so I stuck the gauges on it and crossed our relay to make it stay on and the pressures are perfect 30-40 on low side and
Around 200-210 on high side, mac scanner shows A/C disengage history Rpm unstable and battery voltage, it swaps back and forth to that- battery voltage is right in 14 constantly and current misfire shows no misfires, the misfire history shows a few misfires in cylinder 5 and 7, I just put ac Delco iridium plugs and new wires, also it just had a ac Delco fuel pump installed, I’m kinda at a loss on what to do.. After the vehicles runs for 30-45 minutes the compressor will come on and stay on like it’s suppose to, it’s mainly when I first start it up

repairman54

Could be the refrigerant pressure sensor acting up. I chased a erratic compressor on issue in my old Malibu and that was the issue as it would cycle or not kick in on 90+ days.
On the 'bu it has a Schrader valve under it so no loss of refrigerant.