[fred cook]

Once you have established a good ground, unplug the black wire going to the compressor coil and apply +12v. If the clutch on the compressor is good you will hear it engage and feel resistance when turning the pulley. The trick is to isolate each item rather than trying to feed it thru the system. Once you know that the compressor clutch is good, go on to the next item downstream, probably the relay and apply power there. It will take some time, but doing it this way could save you lots of green by not buying unneeded parts. Good luck!