Hmmmm, nice catch Bob.
If taking off that connector made it quiet, you may indeed need a new compressor.
If it still makes a grinding sound when electrically disconnected, it could still be just the clutch/pulley assembly. I've seen worn/cruddy clutches smoke and scream and the compressor was not seized, but leaking oil from the shaft seal (owner kept putting refrigerant in every few weeks, but no oil). I've also seen compressors seized and when the clutch engages, make smoke, noise and shred the belt. I've seen seized compressors stall the engine.
It sounds like his is impending seizure and the clutch slipped enough to heat things up. The clutch pulley bearing will fail soon since its grease got cooked.
I think we need more information.
2000 2.5 MO5D 4.10 one-wheel drive DD - gave to my older son
1990 STX 87 2.9 going in.....Junked it
2000 3.0 4WD M05D 4.10 S-cab Off-Road package with 235-75-15" tires, hotrod DD, lol