A/C Clutch: Notes

On many models, ECM regulates operation of the A/C clutch through an ECM-controlled relay. This allows the ECM to disengage the A/C compressor when compressor load on engine may cause driveability problems (i.e., during hot restart, idle, low speed steering maneuvers and wide open throttle operation) or if A/C freon pressure drops below or rises above normal operating levels.

Freon pressure sensing may be accomplished by monitoring high and low pressure switches or a pressure sensor which will register either high or low pressure levels. Power steering load is monitored through a power steering pressure switch. Hot restart is monitored through the coolant temperature sensor. For component application and related wiring, refer to A/C wiring schematics under MISCELLANEOUS CONTROLS in appropriate I - SYS/COMP TESTS article in this section.