First you have to determine why the compressor is not engaging before you will know what to look for. All AC systems have some means of disabling the compressor if the system pressure gets too low. If there is a big enough leak, the compressor could put the system into a vacuum, and that could draw in outside air. The humidity in that air combines with refrigerant to form an acid that will attack metal parts. Once the system is recharged, that moisture will circulate and freeze at the orifice tube or expansion valve. That ice will stop the flow of refrigerant until it melts. That typically causes intermittent loss of cooling that can last up to an hour.
There is a low-pressure cut-off switch or a pressure sensor that disables the compressor. The place to start is by measuring the system pressure. If it is low, you will need to search for a leak, then recover the refrigerant that is left in the system, then recharge it with the amount specified.
Friday, March 31st, 2017 AT 3:11 PM