I just replaced my compressor with a new 20lb lighter aluminum one. They are almost identical, bolts right in, with the exception of the 3rd wire that connects at the rear of the original compressor. There is no place for it on the new one. What becomes of this wire? Do I just snip it off, it is spliced to one of the clutch connectors. The wiring scheme shows that it has a diode(?), but, I'm not sure of the purpose.

Thanks, Terry

 

The wire goes to the HSLP (High Side Low Pressure) switch on the back of your Old) compressor. Normally you'd swap the switch from the old compressor to the new...but your new compressor might not have a place for it.

If so, run the wire to ground so the compressor clutch will engage.

The HLSP switch opens (interrupting the ground) to disengage the compressor if the pressure drops due to low freon. It's a protection device to prevent compressor damage. If you don't/can't install it on your new compressor, well, you won't be the first person to go without protection.

Cheers
DDD