Function Selector Knob
WARNING: This page is about a different car, the 1996 Ford Ranger and 1996 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The function selector actuates an 8-port A/C vacuum control switch which controls vacuum control motors at floor, defrost/panel, defrost and outside/recirculation air doors. The function selector also controls on-off operation of the heater blower motor switch and activates the circuit for the A/C clutch circuit in the A/C position.
In following modes, compressor operation is dependent on the A/C cycling switch: A/C (MAX or NORM), FLOOR/DEFROST and DEFROST. See Figure. Cut-out pressure is about 23 psi (1.6 kg/cm2 ). Cut-in pressure is about 46 psi (3.2 kg/cm2 ).