Compressor Controls

The Compressor for the Air Conditioning System is driven by the engine by means of a belt drive and the A/C Compressor Clutch. The Clutch allows the Compressor to be disengaged when Air Conditioning is not required. Power to the A/C Compressor Clutch is supplied by the HTR A/C Fuse.

The A/C Compressor Clutch Diode is connected across the terminals of the A/C Compressor Clutch. Whenever the clutch is de-energized, the magnetic field around it collapses, generating an induced voltage in the clutch coil. The Diode provides a path for the current resulting from the induced voltage so other circuit components are not damaged.

With the A/C-Heater Selector Switch in any mode except HEAT or VENT, voltage flows from the A/C-Heater Selector Switch through the LT GRN (66) wire to the Evaporator Pressure Switch. Battery voltage is passed through the Evaporator Pressure Switch to the A/C Compressor Clutch through the DK GRN (59) wire. The A/C Compressor Clutch Relay. Voltage is also supplied to the A/C Compressor Relay Coil is grounded by the BLK (150) wire. The other side of the coil is grounded by the BLK (150) wire and ground G104. Voltage from the evaporator switch passes through the relay contacts to the PCM or VCM and through the high pressure cutout switch to the compressor coil.