Air Conditioning Relay

A/C Compressor Clutch Relay:

LOCATION

The A/C relay is located in the power distribution center, next to the battery..

OPERATION

When the driver turns on the A/C system, and the engine temperature is below 238° F, a positive voltage signal is supplied to the ECM (as an indication that the A/C system is needed) and to one side of the A/C relay coil.

The ECM determines if engine conditions are suitable for A/C operation (idle speed, ignition timing and air/fuel mixture).

If conditions are suitable for A/C operation, the ECM supplies the ground circuit for the A/C relay coil, energizing it. This allows the relay to supply voltage to the compressor clutch.