The compressor for the air conditioning (A/C) system is driven by the engine through the following components:

When the A/C is not required, the clutch allows the compressor to be disengaged.

Battery voltage is supplied to the heater and A/C controls selector switch through HTR-A/C (fuse 12) and CKT 141 (BRN) when the ignition switch is placed in the RUN position.

An A/C request signal is selected when one of the following A/C functions is selected:

The A/C request signal is created by passing battery voltage to the vehicle control module (VCM). The path for the request follows the following route:

1. CKT 66 (LT GRN) to the A/C high pressure cut-off switch
2. The A/C high pressure cut-off switch to CKT 762 (DK GRN/WHT) to the VCM

The VCM monitors the low pressure switch in the system through CKT 603 (DK GRN). The VCM disables the A/C operation as the pressure drops below a predetermined level.

The VCM produces an A/C enable signal on CKT 459 (DK GRN/WHT) when the A/C request signal is generated. The A/C enable signal will provide a ground for the A/C enable relay coil. Voltage is provided through CKT 639 (PNK) from the IGN-E fuse. The voltage will cause a current flow through the coil of the relay . The current will energize the relay. When the relay contacts are closed the battery voltage will be provided through the following route:

1. From the A/C comp fuse to CKT 1240 (ORN)
2. Through the relay contacts
3. To CKT 59 (DK GRN)
4. To the A/C compressor coil

The A/C compressor coil is grounded by CKT 850 (BLK). The clutch will engage when the current is flowing.

The A/C compressor clutch diode is connected across the A/C compressor coil circuit. The magnetic field around the clutch will collapse when the clutch is de-energized. When the clutch is de-energized, an induced voltage in the clutch coil is generated. The diode provides a path for the current, which is a result of the induced voltage, so that there is no damage to the other circuit components.