Air Door Vacuum Solenoid Valve: Description and Operation

Switchover Valve Unit Location:

PURPOSE

The switchover valves, which are located beneath the dash panel on the heater box, connect the vacuum source to the various vacuum elements.

CONSTRUCTION

The switchover valve unit consists of a plastic vacuum manifold, which is fitted with electrically operated solenoid valves.

OPERATION

While the engine is running, vacuum is supplied to the switchover valve manifold. A vacuum reservoir supplements the system during periods of low engine vacuum and a check valve prevents system bleed off. When the operator selects a climate control function the push-button control unit energizes the appropriate electric solenoid of the switchover valve unit. Vacuum from the engine and or the vacuum reservoir is connected via the switchover valves to the corresponding vacuum element(s) opening or closing the flaps.