Air Conditioning Switch: Description and Operation

PURPOSE
To allow the ECM to control the A/C operation, and make changes in the idle speed and fuel mixture due to the added engine load.

A/C Relay Location:

LOCATION
In the relay box in the front of the drivers side engine compartment

OPERATION
When the A/C system is switched on, a voltage signal is supplied to the ECM. 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, it supplies the ground circuit for the A/C relay coil. This allows the relay to supply voltage to the compressor clutch.

The ECM also maintains the correct fuel mixture and idle speed during the operation of the A/C system.