The air conditioning (A/C) compressor can be identified by a label attached to the body. The label contains the part and model number and the manufacturer's name. The Harrison HR6-HE and the Seltec TM-16HD compressors are belt driven from the engine crankshaft, using an integral clutch through the compressor clutch pulley. The compressor pulley rotates freely, without turning the compressor shaft, until an electromagnetic clutch coil is energized. When voltage is applied to the clutch coil, a clutch plate and hub assembly is drawn rearward toward the pulley. The magnetic force locks the clutch plate and pulley together as one unit in order to drive the compressor shaft.