94 z28 a/c compressor

[littless]

Yes its cold out and don't need a/c right now but i do need to fix the it.
its a 94 Z28
the whole a\c system has been replaced from the compressor, accumulator, expansion valve, pressure switch, dash control switch and PCM.
If I jump the relay it works fine including cooling fans,that's how i charged the system. without the jumper it doesn't work.
I have reset the computer because when it senses low pressure the computer wont let it turn on but no luck.

any ideas?

[5.0THIS]

Of all the parts you replaced, were each of those parts confirmed bad?