Operation CHARM: Car repair manuals for everyone.

System Airflow

INCOMING AIR FLOW
The system pulls outside (ambient) air through the cowl opening at the base of the windshield. Then it goes into the plenum chamber above the A/C-heater unit housing.

DIRECTING AIR FLOW
On air-conditioned vehicles, the air passes through the evaporator. At this point the air flow can be directed either through or around the heater core. This is done by adjusting the blend-air door with the TEMP control on the instrument panel. The air flow can then be directed from the PANEL, BI-LEVEL (panel and floor), and FLOOR-DEFROST outlets. Air flow velocity can be adjusted with the blower speed selector switch on the instrument panel.

RECIRCULATING AIR
On air-conditioned vehicles, ambient air intake can be shut off by closing the recirculating air door to recirculate the air that is already inside the vehicle. This is done by moving the TEMP control into the RECIRC position. Depressing the DEFROST or A/C button will engage the compressor. This will send refrigerant through the evaporator, and will remove heat and humidity from the air before it is directed through or around the heater core.