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. Voltage 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.

The A/C ON input signals the ECM to increase engine idle speed.

The A/C Compressor can be turned off in one of two ways:

1. Moving the Function Lever to the VENT or HEAT position on the A/C-Heater Selector Switch stops the current flow to the system from the HTR-A/C fuse.

2. If the A/C system pressure drops below 172 kPa (25 psi), the Evaporator Pressure Switch opens, stopping current flow to the A/C Compressor.