Air Distribution - Front Control

MODE SWITCH
Use the MODE switch in order to change the air delivery mode in the vehicle. The air flow direction will sequence through the following modes:
^ VENT
^ BI-LEVEL
^ FLOOR
^ MIX-BLEND
^ FRONT DEFROST

VENT MODE
When the driver selects the VENT mode, air is delivered through the instrument panel outlets and a small amount is delivered to the floor. Vacuum is applied to the mode actuator through the Brown vacuum line, and to the defrost actuator through the Red vacuum line. The mode actuator will retract, opening the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

BI-LEVEL MODE
When the driver selects the BI-LEVEL mode, cool air is delivered through the instrument panel outlets while warm air is delivered through the floor outlets. Vacuum is applied to the mode actuator through the Brown and the Blue vacuum lines, and to the defrost actuator through the Red vacuum line. Applying vacuum to both sides of the mode actuator will hold the Vent Door stationary in the half open position. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

FLOOR MODE
When the driver selects the FLOOR mode, air is delivered through the floor outlets with some toward the windshield and side vents. Vacuum is applied to the mode actuator through the Blue vacuum line, and to the defrost actuator through the Red vacuum line. The mode actuator will retract, closing the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

MIX-BLEND MODE
When the driver selects the MIX-BLEND mode, air delivery is divided between the floor and windshield outlets. Vacuum is applied to the mode actuator through the Blue vacuum line, and to the defrost actuator through the Red and the Yellow vacuum lines.

The mode actuator will retract, closing the Vent Door. Applying vacuum to both sides of the defroster actuator will hold the Defroster Door stationary in the half open position. The Heater Door will also be held stationary in the half open position through mechanical linkage.

FRONT DEFROST MODE
If the HVAC system is in front defrost mode when you turn the vehicle off, the HVAC system will restart in front defrost unless the engine is off longer than 40 minutes. If the engine is off longer than 40 minutes, the system will restart in the previous operating mode set prior to using front defrost, with outside air being drawn into the vehicle.

When FRONT DEFROST is selected, the A/C compressor is activated and outside air is brought into the vehicle. Air will be directed toward the windshield with a small amount of air toward the side window outlets. Vacuum is applied to the mode actuator through the Blue vacuum line and to the defrost actuator through the Yellow vacuum line. The mode actuator will retract, closing the Vent Door. The defroster actuator will retract, opening the Defroster Door and close the Heater Door through mechanical linkage. Recirculation mode is not available in front defrost. The rear window defogger does not affect the HVAC system at all.

OUTSIDE AIR MODE
When the OUTSIDE AIR switch is toggled, outside air is brought into the vehicle. This mode has no effect on the system when FRONT DEFROST mode is selected. OUTSIDE AIR and RECIRCULATION are separate modes and are not available together.

RECIRCULATION MODE
When the recirculation switch is pressed, a solenoid inside the HVAC control module connects the recirculation vacuum actuator to the vacuum source. Power is provided to the recirculation switch by the ignition 3 voltage circuit. Ground is provided by the ground circuit and splice pack. The recirculation actuator retracts, closing the recirculation door. This brings air from inside the vehicle instead of fresh air from the outside.

Recirculation is available in all modes except FRONT DEFROST and MIX-BLEND. The recirculation mode will stay on and the LED will illuminate until either outside air or a non-recirculation mode is selected. The HVAC control module will stay in recirculation mode for 30 minutes after the ignition switch has been turned off. Recirculation can be selected with the blower motor in either the ON or OFF position.