2006 Air Conditioner issues.

James Hinton · August 17, 2020

I hope everyone is doing alright and thank you in advance for any help or insight into my problem.

I have a 2006 Silverado 1500 Z71 LT crew cab, 5.3L with 217,000 miles and have been having air conditioner cooling issues for some time. Some history, I bought the truck in 2014 with 114,000 miles and had very little issues until about a year ago. I have replaced the infamous blower motor resistor probably three times and the blower itself once. Last summer the actual climate control module in the dash went out and I replaced it with one from O’Riley’s auto parts, this is the module with “Auto” and is has the digital display with separate controls for driver and passenger. Shortly after replacing the module I noticed often, but not consistently at an idle the AC would be blowing hot air. I had the Freon checked and the pressures were good, when it was blowing cold. I eventually found that if I increased the RPMs that I would hear a bump from under the hood, what I thought was the AC compressor engaging but not sure, and the AC would start blowing cold again and sometimes it would start blowing cold again on its own. There were also times when I could turn the ignition off and restart the truck and it would begin to blow cold. I have talked to several mechanics and none have any idea as to what may be causing this, so I was hoping maybe one of you could help. I was not sure if something in that climate control module activates the compressor or what the problem could be.

sefiroxx · August 17, 2020

Could be Freon pressure sensor, air temp sensor, relay, etc

You'll need a meter and full ac guages for diagnostics.
- hook up guages and verify static pressure is at 70-90 with ac off.
- monitor guages for when the system shuts off looking for low pressure below 30 or high above 250/275 300 (depending on outside temp)
- meter to chase electrical signal from controller to blower and the control signal to the Compressor.

chem_man · August 18, 2020

I would also check your fan clutch for proper operation. While you are at it, take a garden hose with a nozzle and wash your radiator and condenser from the engine side.