Normal Operation

WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Under normal operation, when A/C is requested, voltage is sent from the electronic automatic temperature control (EATC) module or function selector switch to the A/C cycling switch through circuit 348 (VT). Voltage is sent from the A/C cycling switch to the (gasoline engine) A/C high pressure switch or (diesel engine) dual function pressure switch through circuit 441 (RD/YE). Voltage is sent from the A/C high pressure switch or dual function pressure switch to the powertrain control module (PCM) through circuit 439 (TN/RD).

The PCM provides a ground for the A/C clutch relay coil through circuit 331 (PK/YE). The A/C clutch relay coil receives ignition voltage through circuit 391 (RD/YE). Ignition voltage for the A/C clutch relay switch is provided through circuit 326 (WH/VT). When the relay is activated, ignition voltage is supplied to the A/C clutch solenoid through circuit 321 (GY/WH). Ground is supplied for the A/C clutch through circuit 57 (BK).