Manual A/C

The air delivery system directs the flow of air used by the automatic climate control system.

The automatic climate control unit receives battery voltage at all times through fuse 33. With the ignition switch in RUN, battery voltage is supplied to the control unit through fuse 4. The automatic climate control unit is grounded at G401.

Each of the plenum door motors is driven and controlled by the automatic climate control unit.

The automatic climate control unit applies a reference voltage to each of the four door position switches in the mode control motor. The control unit determines the position of the door by grounding various combinations of position switches. For example: if the BLU, PNK/BLK and GRY wires are grounded, the door and motor move to the HD2 position.

The air mix control motor limit switches and diodes interrupt voltage to the motor when the air-mix door reaches the end of its travel. During start-up, the motor is turned on by the control unit to learn the position sensor readings for its range of travel. The position sensor varies resistance to provide feedback of the door's position through the GRN wire.

The vent door control motor limit switches and diodes interrupt voltage to the motor when the vent door reaches the end of its travel. During start-up, the motor is turned on by the control unit to learn the position sensor readings for Its range of travel. The position sensor varies resistance to provide feedback of door position through the YEL/WHT wire.

The recirculation control motor limit switches interrupt voltage to the motor when the door reaches the end of its travel. A position sensor is not required for this door since operation is only in the full fresh or full recirculation position.