Vacuum Sensor / Switch HVAC: Description and Operation

HEATER CONTROL VALVE VACUUM SWITCH

The heater control valve vacuum switch to control operation of the heater control valve. The heater control valve vacuum switch:
- is mounted on the RH side of the heater core and evaporator core housing just below the defrost door vacuum control motor.
- is actuated by an arm attached to the temperature blend door RH pivot shaft.
- applies vacuum to the heater control valve when the temperature blend door is in the full COOL position.