System Description

BASIC OPERATION STRATEGY
The air conditioning switch applies battery positive voltage to the engine control module when the air conditioning is switched ON.
When the air conditioning signals are input, the engine control module activates the idle air control motor, and also switches ON the power transistor. As a result, current flows to the compressor clutch relay coil and the relay switch is switched ON; the air conditioning compressor's magnetic clutch is activated.

TROUBLESHOOTING HINTS
If the air conditioning compressor's magnetic clutch is not activated when the air conditioning switch is switched on during idling, the cause is probably a malfunction of the air conditioning control system.