Operation CHARM: Car repair manuals for everyone.

Heater System

PURPOSE
The air conditioning system operates on the reheat principle in that all the air passing through the system is chilled almost to a freezing temperature and then reheated to a more comfortable temperature before it is discharged into the passenger compartment.

OPERATION
The dehumidified air is reheated as it passes through the heater core in the air conditioning module. The heater is warmed by engine coolant passing through the tubes of the heater core. This heat is transferred to the heater core fins and given off to the air flowing past the fins. The position of the air temperature valve in the air conditioning module determines how much of the total airflow is allowed to pass through the heater. In turn, this determines the warmth of the total airflow discharged into the passenger compartment.