Pic. 2.269. Wiring diagram for air conditioning relay and computer
When you turn on the air conditioner on the engine control unit from the air conditioner switch (pic. 2.269) battery voltage is applied. Having received the signal to turn on the air conditioner, the ECU issues a command to the idle speed controller and turns on the power transistor of the ignition system. After that, the winding of the power relay of the air conditioner is energized, which works and turns on the electromagnetic clutch of the air conditioner compressor.