QuestionI have a 95 golf GL 2.0. when the engine temp. is cold the a/c will work until the engine temp. reaches the normal operating temp. then the a/c compressor will shut off and not come back on. I have changed the compressor, condenser, and the receiver dryer can u pls. help.
AnswerHi Cliff;
To me it sounds like one of the "protection" devices is going off prematurely. It sounds like you have a manifold and gauge set. Put it on the system, and watch the pressure on the high side/discharge side. If the pressure at the TXV(thermal expansion valve) goes up to 200psi the high pressure cutoff/cutout switch is probably the problem. Just to make sure though, use a couple of pieces of wire, strip the insulation, in the middle, and put a DVOM(digital volt ohm meter) and watch the resistance at the high pressure switch. If the switch resistance drops to at or near zero ohms when the car heats to 80-85 degrees Celsius, then it's the high pressure switch. However, it could also be the low pressure switch. The high one is up near the bulkhead on the right side of the car, I think that's the high one. The low one is at, or near the condenser, I think. At any rate, if the TXV opens too much, no cooling will take place, but worse yet is the system pressure will drop, a lot, and real fast, so the low pressure switch will shut the compressor off. Same tests, opposite results to find out which one is not working properly. At least those are what I would start with. I suppose there could be one other possibility, and that is the circuit that feeds the electromagnetic clutch drive at the compressor itself, but if it is new, that is the least likely place, at this time.
Thanks for the question, Cliff. Hope this helps you solve your problem.
