A/C Compressor Controls

Voltage is provided at all times to the A/C compressor clutch relay contacts through fuse 12 (in the under-hood fuse/relay box). With the ignition switch in ON (II), voltage is supplied to the relay coil through fuse 30 (in the under-dash fuse/relay box).

With the ignition switch in ON (II), the HVAC control unit (USA: RT; Canada: DX, VP) or climate control unit (USA: RTS, RTL; Canada: EX-L; Mexico; Latin America) grounds the A/C ON input of the PCM through the A/C pressure switch. The PCM then grounds the A/C compressor clutch relay coil. This energizes the coil, which closes the relay contacts and provides voltage through fuse 12 (in the under-hood fuse/relay box) to the A/C compressor clutch. The clutch then engages and begins turning the compressor. By default, when the HVAC control unit (USA: RT; Canada: DX, VP) or climate control unit (USA: RTS, RTL; Canada: EX-L; Mexico; Latin America) system is on, the A/C is on also.