Water Control Valve

The Water Control Valve is a three-position two-vacuum port water valve that regulates coolant flow to the rear compartment heater core. Its three positions (Wide-Open, Restricted and Closed) are controlled by vacuum applied to ports 1 and 2 of the valve. The application of vacuum to these ports is controlled by the Water Control Solenoid (port 1) and the Heater Control Assembly (port 2). When the Water Control Solenoid is energized, port 1 of the valve is vented and port 2 is mechanically overridden, causing the valve to be in the Wide-Open position. This position is required for filling the cooling system. With the Heater Control Assembly in the "HTR-DEF" Mode ("OFF," "HTR," "DEF," "MIX") and the Auxiliary Blower Switch in an "ON" position, vacuum is applied to port 1 and port 2 is vented, causing the valve to be in the Restricted position, limiting coolant flow to the rear heater core. The Rear Vacuum Door will direct air to the floor and window vents. Placing the Heater Control Assembly in the "Upper" Mode ("MAX," "A/C," "VNT," "BIL"), both ports 1 and 2 have vacuum applied, causing the valve to be in the "Closed" position, preventing coolant flow to the rear heater core. The Rear Vacuum Door will route air to the overhead vents.