debrockle

Per advice of Txab: Tap Tap engage... So that action worked. Assume a failing or failed clutch then? I am going to start researching this now.. but in all of your experience is this something that a garage mechanic can fix without removing the compressor? Or new compressor/clutch unit... or is there a way to clean the clutch for better operation? Thanks again for all the advice and any help in the future.

Apologies. I did reset the HVAC as you suggested prior to all the troubleshooting. It did not correct the issue. Unit fired up at 74 degrees. Ran for two minutes. Shut off for 10 seconds.. fire engine back up. No joy...

Good Evening all. apologize for the novel but bear with me...I need a hand troubleshooting before the local dealer takes me to sizzlers. 2006 GMC Sierra 1500. Dual manual Climate controls. Crew Cab. 5.3 Liter. I have an issue with the air conditioning ceasing to cool while driving after about 20 minutes (what seems). The only way I can get the truck to start cooling again (compressor to re-engage) is if I restart the vehicle ( or if I plug in the OBDII Code tester, more on that later). I have taken the vehicle in for service twice. Once to check the refrigerant level which was fine. Second time they replaced the low pressure cycling switch off the dryer/accumulator (which seemed to be a common fix according the internets). All with no joy. I have a OBDII scanner and it shows no codes. Today I made the connection that the compressor seems to stop when I bring the system off full dual cool to a warmer setting where the truck should be trying to maintain a cabin temp instead of full blast. Once all the fans slow down is when I seem to lose the compressor and the cooling even if I try full cold again. I repeated this failure while driving 3 times. However, while parked this issue doesn't seem to happen cycling the full cold to warmer.. cabin maintaining and back to cold. Very frustrating. Final note: while checking the last time while driving and the compressor had stopped I brought it back to my garage... plugged in the scanner prior to restart to see if a code had popped. When I plugged that scanner in.. the truck did its normal thing being tested (kinda a flash on the dash).. however it also "reset" the compressor and it started again... and cooling like a champ without a restart. So in a nutshell this is where I am. Refrigerant is good. low pressure cycling switch is new on the accumulator. Lose the cooling/compressor when the cabin is not full blast and maintaining cabin temp. Restart will bring compressor back to life or plugging in OBDII scanner. So pretty sure the mechanical side is good. What is next to check or replace? HVAC control head? check another sensor? Please help. Sorry about the novel.. but been at this for a while. Hagendaus