Control Assembly, HVAC

Heater A/C Controls

The knobs and buttons on the control head control the operation of the A/C system. The compressor clutch and blower are connected electrically to the control head by a wiring harness. Air flow is provided at one of 5 available blower speeds. Cooled and dehumidified air is available in all modes. A/C compressor operation is forced in the following modes:

^ Defog mode
^ Defrost mode

A/C compressor operation is available in the remaining modes by pushing the A/C button-to-light indicator. Low ambient temperatures will not permit the operation of the A/C compressor.

The temperature knob controls the temperature valve through a potentiometer in the control. Vacuum actuators control the modes of operation. The vacuum actuators control the flow of vacuum on the various vacuum valve positioning actuators. The knob on the left controls the blower motor speed. Turning the knob to the right increases the motor speed. The blower is turned off in the OFF position. Temperature valve position is independent of mode selection.