I just put "ALL" new A/C parts in. I know some about A/C systems but not operations. I've restored hundreds of 1967 to 1973 in-dash Mustang and Cougar A/C systems but never installed or charged them. I've installed "ALL" completely new parts in a 1992 Mustang and 1994 Mazda B3000 but had someone charge them and didn't watch. This time I had someone do this but now exactly sure if he knew what he was doing. Seems I knew more than he did in some parts of this. We evacuated the system and held pressure so no leaks. We charges the low side to about 50 but he didn't want to go over since he says is could blow the compressor. He seemed to have a problem getting a reading on the high pressure side but finally got about 120 to 130 and told me it should be 250 to 275. The air comes out cool but not cold. Question is... What "SHOULD" the pressures be and if the low side is correct why is the high side so low. I'm assuming it's the compressor even though it's new. The pipe part of the high side around the port is really hot. The compressor doesn't cycle and I assume that's because the evaporator isn't getting cold enough to cause the compressor switch to switch off. Any ideas what's going on???