Air Delivery: Defrost

When DEFROST is selected, dehumidified air is delivered to the windshield outlets. Vacuum is applied to the mode actuator through the Blue vacuum line, and to the defroster 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.