Temperature Valve and Heater Core

The temperature of the air discharged from the heater system is regulated by controlling the relative amounts of warm and cool air that are mixed together downstream from the heater core area. The part of the total airflow that is allowed to pass through the heater core is governed by the position of the temperature valve.

Hot coolant from the engine's cooling system is directed through the heater core. The heater core transfers heat from the coolant to the air passing through the fins.