Air Cleaner - Thermostatic: Operation

When temperature of air entering air cleaner is less than setting of temperature sensor, sensor closes. This allows engine vacuum to operate vacuum motor, which closes damper assembly to outside air. Heated air is then drawn from around exhaust manifold, through heat shroud and into air cleaner.

As air inside air cleaner warms, sensor valve begins to open. This bleeds off vacuum to vacuum motor. As vacuum to vacuum motor drops, air control door begins to open. This allows outside air to enter air cleaner. When air entering air cleaner reaches a specified temperature, air control door opens completely, thus closing off supply of heated air from around exhaust manifold.