Heating And Air Conditioning - Operation

OPERATION

NOTE: Typical blend-air type HVAC system shown.





The heating and A/C systems used in this vehicle are a single zone, blend-air type system. In this blend-air heating and A/C system, two blend-air doors (3) control the amount of conditioned air that is allowed to flow through, or around the heater core (2).

The system pulls outside (ambient) air through the fresh air intake (4) located at the cowl panel at the right side base of the windshield and into the air inlet housing, inside the passenger compartment. From there, the ambient air passes through the A/C evaporator (7) and is then directed either through or around the heater core. This is done by adjusting the position of the blend-air doors with the temperature control located on the A/C heater control in the instrument panel. Air flow is then directed out the floor outlets (8), instrument panel outlets (10) or the defroster outlets (1) in various combinations by adjusting the position of the mode-air doors (9 and 11) using the mode control located on the A/C heater control. The Automatic Temperature Control (ATC) system uses electric actuators to operate the blend and mode air doors. The Manual Temperature Control (MTC) system uses cables to operate the blend and mode air doors.

The velocity of the air flow out of the outlets can be adjusted with the blower speed control located on the A/C heater control.

The fresh air intake can be shut off by the Recirculation control, located on the A/C heater control. This will operate the electrically actuated recirculation-air door (5), which closes off the fresh air intake. With the fresh air intake closed, the conditioned air within the vehicle is pulled back into the HVAC housing through the recirculation air intake (6), located within the passenger compartment.

NOTE: It is important to keep the fresh air intake opening clear of debris. Leaf particles and other debris that is small enough to pass through the cowl opening screen can accumulate within the HVAC housing. The closed, warm, damp and dark environment created within the housing is ideal for the growth of certain molds, mildews and other fungi. Any accumulation of decaying plant matter that enters the housing with the fresh ambient air provides an additional food source for the fungal spores. If the air intake opening is not kept clear of debris, objectionable odors created by growing fungi and decaying plant matter, as well as excess debris, can be discharged into the passenger compartment during heater and A/C operation.

The A/C compressor can be engaged by pressing A/C (snowflake) button on the A/C heater control. When equipped, the A/C compressor will automatically engage when the mode control is set in any Mix to Defrost position. This will remove heat and humidity from the air before it is directed through or around the heater core.