Compressor

The compressor is located at the lower front right side of the engine, and is direct mounted to the engine. The compressor's function is to compress low pressure refrigerant vapor into high pressure, high temperature vapor.

The compressor is a variable displacement rotary vane type pump. The compressor uses a control valve to automatically vary its displacement as system heat loads change. The displacement can vary from 6.5 percent (9 cc) to 100 percent (140 cc).

The electromagnetic clutch engages the compressor when the A/C button in depressed. The clutch consists of a drive plate, pulley, and a coil assembly. The drive plate is bolted to the compressor shaft. The pulley and bearing assembly is press fit onto the compressor hub, and the coil assembly is screwed to the compressor body. A thermal link fuse is incorporated into the coil. If the temperature of the coil exceeds 214°C ± 3°C, the link will melt creating an open coil circuit. When the coil is de-energized the drive plate releases the pulley and the compressor stops pumping. A typical coil resistance will measure 3.22 ± 0.08 ohms at 72°F.

A diode is used to protect the vehicles electrical circuits from the collapsing electrical field of the coil. This diode is located in the UHFB.

To protect the A/C system from high pressure, a pressure relief valve is located in the front head of the compressor. This valve will open at 3620+345/-245 kPa (525 psi) and reseat at 2930 kPa (425 psi). If this valve ever opens the A/C system must be serviced and the valve must be replaced.