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Join Date: Apr 2011
Location: SO CAL...Huntington Beach and Rancho Cucamonga
Re: EXPRESS 2500 AC Problem
Hows your engine cooling temp? Running high? Some of these newer pos systems will shut down and leave you sweating if the engine temp reaches a certain point.
My 2005 Silverado wouldn't turn on the compressor, ened up changing the control head in the dash to get it working.
Hook up your gauges this weekend and check operating pressures. You could have a blockage/high-pressure situation or low charge, the only way you'll know is by gauge readings. You could also have a faulty low or high pressure switch or poor electrical connections to them.
The only way I can work through these newer systems is page by page in the manual. They are a pain in the butt. All the moons and planets need to align to get them to work.
If that a/c shop didn't pull out the ohmmeter and gauges, it sounds like they will throw the kitchen sink at it and see if something sticks. They'll do that just to find out that it's an electrical/module issue.