My compressor was not turning on just before a trip and I needed the a/c so I hooked up a lead to the bat +, switched in the car and connected to the compressor. It worked fine. I turned on the compressor when needed and turned it off when not needed. The connection to the compressor bypassed the Hi and Lo pressure swithches and was for short term use. You can interrupt at this point if all you will do is turn off the compressor.