Heater System
The heater system heats air entering the vehicle passenger compartment. The main component of the heater system is the heater core, a small radiator located inside the passenger compartment. Engine coolant is pumped to the heater core directly from the engine whenever the engine is running; no water valve is used. The engine coolant transfers heat to the heater core tubes and fins; air passing over the fins on its way to the passenger compartment then absorbs this heat.