General Information

Blend Air Heater A/C System:

DESCRIPTION
All vehicles are equipped with a common heater A/C unit housing assembly. When the vehicle has only a heater system, the evaporator and recirculating air door are omitted from the heater unit housing assembly.

Heater A/C Controls:

OPERATION
These systems both draw outside (ambient) air through the cowl opening, into the plenum chamber of the heater-A/C unit housing. On air-conditioned vehicles, the air then passes through the evaporator. At this point, the air flow can be directed either through or around the heater core by adjusting the blend-air door with the TEMP lever on the instrument panel control. Then, the air flow can be directed from the PANEL outlets, BI-LEVEL (panel and floor) outlets, FLOOR DEFROST (side window demister if so equipped) outlets. The airflow velocity can be adjusted by the blower speed selector switch on the instrument panel control.

On air-conditioned vehicles, ambient air intake can be shut off by closing the recirculating air door to cool the air that is already inside the vehicle. This is done by moving the TEMP lever into the RECIRC position. Depressing the Defrost or A/C button will allow refrigerant to flow through the evaporator to cool and dry the air before it is directed through or around the heater core.

SIDE WINDOW DEMISTERS (IF EOUIPPED)
The side window demisters direct air from outlets located on the top, outboard corners of the instrument panel when the control mode selector is on FLOOR (heat) or DEFROST setting.


OUTSIDE AIR VENTILATION
Forced-Ventilation is directed from the instrument panel and/or floor outlets when the heater A/C control mode selector is on panel or bi-level setting. The temperature of the forced-vent can be regulated with the temp lever on the heater A/C control.

ENGINE COOLING SYSTEM REOUIREMENTS
The use of a bug screen is not recommended. Any obstructions forward of the radiator or condensor can reduce the effectiveness of the air conditioning or engine cooling system.