Air Delivery System

Airflow:

The heating and air conditioning module incorporates most of the air delivery components into one assembly.

Air utilized by the system is drawn into the module through an opening at the base of the windshield and routed to the blower. The blower directs the air through the evaporator core where it is filtered, dehumidified, and cooled to approximately 2°C (35°F). It is then heated as required by passing through and around the heater core. This air is then directed by air valves to the A/C outlets in the instrument panel, to the heater outlets at floor level, or to the defroster outlets depending upon the mode selected. Air exits from the interior by passing through the air exhaust grilles located in the door lock pillars or rear quarter.

Air Intake

Air intake is controlled by an air inlet valve and a vacuum actuator that controls the position of the valve. The air inlet valve has two positions. With no vacuum applied to the actuator, the valve is in its down position, blocking off the recirculating air opening and allowing only outside air to enter the blower.

When vacuum is applied to the actuator, the valve is moved to its up position, where it blocks most of the outside air and allows approximately 90 percent of the total air supply drawn in by the blower to be recirculated from the passenger compartment.

Blower Motor

The blower motor is located left of center in the A/C module. The blower motor is a brush less type and operates at various speeds determined by the heater and A/C programmer. The balance of the brushless blower motor is very sensitive to handling. When the blower motor is serviced, care should be taken to minimize the amount of blower motor handling.

Console Blower Motor

Some vehicles may be equipped with a blower motor that is located within the console which assists in providing airflow to the rear seat passengers. The blower speed is controlled by a switch located at the rear of the console.