Ranger 4WD V6-3.0L VIN U (1997)
Air Door Actuator / Motor: Description and Operation
Vacuum System Schematic
The outside/recirculating inlet air door is vacuum-operated. The Vacuum Diagram illustrates, in schematic form, how system components are involved.
The recirc. door is controlled by a vacuum control motor, which is powered by engine intake manifold vacuum. The function selector in the A/C control
sets the door in either of its two operating positions: (1) closed to the vehicle interior (outside air position) when no vacuum is applied, or (2) open to the
vehicle interior (recirculated air position) when vacuum is applied. In vehicles with A/C, vacuum is applied when the function selector is placed in the
MAX A/C or OFF position only. This is to allow the driver of the vehicle the opportunity to improve the air conditioning performance in hot weather by
cooling recirculated air or the opportunity to shut off the flow of outside air. (In heater-equipped vehicles, vacuum is applied to shut off outside air in the
OFF position.) In all other function selector lever positions (PANEL, PNL/FLOOR, FLOOR, FLR/DEF, or DEFROST), no vacuum is applied and the
door remains closed to the vehicle interior. The inlet air door position can be observed through the recirculating inlet, located below the glove
compartment.