It was r12 in the system, went back and looked at the records when the a/c system was redone. I disconnected the compressor and there was no freon in it, which must be the reason the compressor froze up. At first I thought it was just the clutch that went out, but the compressor when turned manually grinds. The o-ring on the back had a big gouge, so I assume that is where the leak was. Need to put a vacuum on it once I get the new compressor installed.

I am thinking the freon as well as oil leaked out and caused the clutch to fail. Any thoughts?