Heater/Defrost Valve

The Heater/Defrost Valve can assume three positions and is operated by a Bi-Directional Vacuum Actuator which can move the valve to either of two positions. If no vacuum is applied to either Vacuum Actuator, the valve is in midposition. Air flow with the valve in the midposition (B) will be delivered to both the Defrost Outlets at the windshield and the Heater Outlets at floor level. When the Heater Vacuum Actuator is operated, the valve moves to position (C), forcing all air flow to the Heater Outlets. When the Defrost Vacuum Actuator is operated, the valve is moved to position (A) which will force air flow to the Defrost Outlets.