Front Defrost

When the driver selects the FRONT DEFROST mode, the blower motor turns ON. The driver may manually adjust the blower speed. If the outside temperature is above 8°C (48°F), the following actions occur:
^ The A/C LED illuminates.
^ The compressor activates.

The compressor runs in order to maintain the evaporator core at about 1°C (33°F).
The vacuum actuators move to the following positions:
^ The heater and A/C programmer supplies vacuum to one side of the heater-A/C bi-level valve.
^ The air-inlet valve vents in the outside air position.
^ The defrost-A/C valve vents in the defrost position.
^ The heater-A/C bi-level valve vents in the A/C position.

The blower pulls outside air into the system. The air is cooled, dehumidified and heated. The air is then forced through the windshield defroster outlets.The heater and A/C programmer performs the following functions:
1. Determines the proper air discharge temperatures
2. Positions the air mix valves accordingly