Fleetwood FWD V8-252 4.1L (1986)
Heater Water Control Valve: Description and Operation
The heater water valve is located at the right rear of the engine compartment. This valve passes or blocks flow of engine coolant to the heater core. The
valve is normally open, allowing hot engine coolant from the engine to flow to the heater core, but is closed by vacuum from the programmer solenoid
valve when the BCM sends an appropriate signal. The BCM closes the heater water valve whenever the air mix door is in the MAX A/C position.