I am having trouble with the a/c on a '97 chevy 1 ton. We recently purchased a new gooseneck trailer. Upon plugging in the 7 prong adapter into the truck, I noticed the a/c compressor quit working. Disengaging the adapter it started to work again. The dealer replaced the cabin filter and recharged the system. Of course this did nothing to resolve the matter and went on for over a year. I took the truck to another shop to have them try their hand at it . They recharged the system and found the high side port to be leaking. It was working great until I plugged the trailer in again. Now the compressor doesn't work at all. I checked the fuses relating to the a/c and swapped the compressor relay module with the starter module(identicle modules) and the truck started fineproving the module is good. This is where I am at now.

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