Hi, I just had my A/C renewed (80 300SD) and it works well, but it seems to place a LOT of resistance on the engine -- the engine temp gets quite high, about 200F.

But more important, today, I turned off the compressor, then turned it back on, and the engine stalled. Couldn't start it again when compressor turned on. If started again without compressor, then I turned it on, the engine would stall, strange sound from compressor.

I stopped messing around, waited an hour, then it started up fine again.

Isn't there supposed to be some protection to make sure the compressor doesn't turn on when there's too much high-side pressure (is this the correct terminology? I'm learning this today, but I do remember that for example it's bad to turn your house A/C off and then on quickly)? I wonder if the pressure valve on the evaporator/drier is for this function? or is that to just make sure there is enough refrigerant? I'm being told the guy might have seriously overcharged my system.

Thanks a lot...