Hi Everyone!

My AC is giving me problems.....AGAIN. The compressor went last year so I had it replaced with a used one. I don't think the mechanic knew what he was doing and it stopped working after awhile. Maybe not enough R-134A? The compressor doesn't even cycle now. I assumed this was because it needed a recharge so today we bought a can of R-134A with a gauge on it. With the car running and the AC on, we hooked it up and the gauge read "empty". We started filling it (less than a minute's time) and the gauge went into the "filled" spot at 45psi. What the heck is going on and what should I do? As you know from my other posts, I have no idea what I'm doing. I've read every AC post on this forum but still I'm having no success with my AC. Please help if you would???? Be as specific as possible so I can understand what you're telling me, okay? I sure appreciate any help someone would give me!!!!!!! Thanks!!!!!!