1987 BMW 325

A/C fuse blew. Replaced and Blew again. Replaced and this time did not blow, but no cold air. Checked A/C compressor and the magnetic clutch will not engauge when A/C button on dash is pressed. Blower works. I see what appears to be a diode on the Compressor. How do you test the magnetic clutch and or diode without removing the compressor? I would like to troubleshoot the problem without taking everything apart. The A/C was working fine, putting out plenty of cold air and running on a long trip for over and hour when it died.
If the wires going to the compressor need to be removed for the test, how do they detach. It is dark down there and I can't see them that well. I just don't want to pull on them and break them. If the clutch is to be removed, how do you do it without disconnecting all the hoses and loosiing the R-12?