Defroster Valve

The defroster valve can be moved to 1 of 3 positions. The defroster valve actuator consists of 2 chambers operated by 2 vacuum actuators. When the A/C system is operated in the bi-level of the DEFOG mode, neither vacuum chamber is evacuated and the door is in position B. Air flow is then directed to both the defrost outlets and heater outlets. If the heater solenoid is activated, the actuator moves the valve to position C. Position C directs air flow to the heater outlets (lower mode). If the defrost solenoid is activated, the valve moves to the defrost outlets. This is the position the valve is in when operating the defrost mode.