System Operation

MAX A/C
When MAX A/C is selected:
^ The recirculation air duct door is at full vacuum, closing off outside air and admitting only recirculated air.
^ The floor/panel door and the floor/defrost door are at the full vacuum position, directing airflow to the A/C register.
^ The temperature is usually set for maximum cold but may be heated if desired.
^ Air will be picked up at the recirculation opening by the blower motor. With the A/C control set for maximum cold, airflow across the evaporator core will be diverted past the heater core and then directed into the passenger compartment through the instrument panel A/C register. There is also some airflow to the A/C side window demisters.
^ The A/C compressor will be enabled when MAX A/C is selected.
^ The blower motor is on.







NORM A/C
When NORM A/C is selected:
^ The recirculation air duct door is in the no vacuum position, blocking recirculated air and admitting outside air.
^ The floor/panel door and the floor/defrost door are at the full vacuum position, directing airflow to the instrument panel A/C registers.
^ The temperature may be raised if desired.
^ The A/C compressor will be enabled when NORM A/C is selected.
^ The blower motor is on.







VENT
When VENT is selected:
^ The recirculation air duct door, with no vacuum being applied, will block recirculated air and admit outside air. From there, air flows through the system to the instrument panel A/C registers.
^ The floor/panel door is in full vacuum position to block airflow to the heater outlet floor duct.
^ The floor/defrost door is at full vacuum, closing off airflow to the windshield defroster hose nozzle. There is also some airflow to the A/C side window demisters.
^ The temperature can be adjusted to heat the air but air cannot be cooled below outside temperature.
^ The A/C compressor will be disabled when VENT is selected.
^ The blower motor is on.







OFF
When OFF is selected:
^ The recirculation air duct door is at full vacuum, closing off outside air and admitting only recirculated air.
^ The floor/panel door is in the no vacuum position, closing the passage to the instrument panel A/C registers.
^ The floor/defrost door is at full vacuum, closing the passages to the windshield defroster hose nozzle.
^ The blower motor and the A/C compressor are off.







FLOOR
When FLOOR is selected:
^ The recirculation air duct door is in the no vacuum position, blocking recirculated air and admitting outside air.
^ The floor/panel door is in the no vacuum position, blocking air circulation to the instrument panel A/C registers.
^ The floor/defrost door is in the full vacuum position, directing all airflow to the heater outlet floor duct.
^ The temperature can be adjusted to mix air flowing through and around the heater core to achieve the desired temperature level.
^ The A/C compressor will be disabled when FLOOR is selected.
^ The blower motor is on.







MIX
When MIX is selected:
^ The recirculation air duct door is in the no vacuum position blocking recirculated air and admitting outside air.
^ The floor/panel door is in the no vacuum position, blocking air circulation to the instrument panel A/C registers.
^ The floor/defrost door is in the partial vacuum position, allowing airflow to both the windshield defroster hose nozzle and the heater outlet floor duct. There is also some airflow to the A/C side window demisters.
^ The A/C compressor will be enabled when MIX is selected to dehumidify the air and reduce windshield fogging.
^ The blower motor is on.







DEFROST
When DEFROST is selected:
^ The recirculation air duct door is in the no vacuum position, admitting outside air.
^ Both the floor/defrost door and the floor/panel door are in the no vacuum position so that most of the incoming air is directed to the windshield defroster hose nozzle. There is also airflow to the A/C side window demisters.
^ The temperature setting will determine the amount of air that is directed through the heater core and the amount that bypasses the heater core.
^ The A/C compressor will be enabled when DEFROST is selected to dehumidify the air and reduce windshield fogging.
^ The blower motor is on.

Electrical Components, Part 1:

Electrical Components, Part 2:

Climate Control System Electrical Components