gdeg12

I am having trouble getting the a/c working in my truck. It holds freon and does not have any leaks. The pressures are correct, but the compressor will not flip on. I checked the fuse and relay, both are good. I "jumped" the compressor and it turned on, but no cold air would blow out. After a minute or two of running, freon would spray out of the pressure relief valve. I was thinking maybe I have a bad pressure relief valve, but that does not explain why the computer is not communicating with the ac compressor. Any clues before I pay big money for this to get fixed? *I have auto temp control*