Fig. 2.269. Wiring diagram of the air conditioner relay and the ECU
When the air conditioner is switched on, the battery voltage is supplied to the engine control unit from the air conditioner switch (Fig. 2.269). Having received the signal to switch on the air conditioner, the ECU issues a command to the idle speed controller and switches on the power transistor of the ignition system. After this, the winding of the air conditioner power relay is energized, which is triggered and switches on the electromagnetic clutch of the air conditioner compressor.