Mustang V8-5.4L SC (2008)
Compressor Clutch Relay: Description and Operation
AIR CONDITIONING (A/C) CLUTCH RELAY (A/CCR)
NOTE: The PCM PIDs WAC and wide open throttle air conditioning cutoff fault (WACF) are used to monitor the A/CCR output.
The A/CCR is wired normally open. There is no direct electrical connection between the A/C switch or electronic automatic temperature control (EATC)
module and the A/C clutch. The PCM receives a signal indicating that A/C is requested. For some applications, this message is sent through the
communications network. When A/C is requested, the PCM checks other A/C related inputs that are available, such as A/C pressure switch and A/C
cycling switch. If these inputs indicate A/C operation is OK, and the engine conditions are OK (coolant temperature, engine RPM, throttle position), the
PCM grounds the A/CCR output, closing the relay contacts and sending voltage to the A/CCR.
