Ac won't blow cold on 1994 Volvo 940

my ac is blowing hot air even after I charge it. When I turn it on the compressor does not chip in but when I check it, it seem to be working fine. what could cause it to blow hot air?

Asked by for the 1994 Volvo 940
I don't fully understand. Is the compressor running? What is "running fine"?
the compressor doesn't run when I turn the ac on but when I test the compressor separately, it seems to be working fine
OK, got it. So the compressor is not getting power to operate. You'll want to verify that the power is being sent from the A/C control panel. You'll need a wiring diagram and a test light (or volt meter) to do this. You can get a wiring diagram here: