System Operation

MAX A/C
When MAX A/C is selected:
^ The A/C damper inlet duct door is at full vacuum, closing off outside air and admitting only recirculated air.
^ The heater air damper door is at full vacuum, directing airflow to the instrument panel A/C registers.
^ The windshield defroster door is at full vacuum, closing off airflow to the windshield defroster hose nozzles.
^ Temperature control is usually set for full cool, but may be heated if desired.
^ Air will be picked up at the recirculation opening by the blower motor. With the temperature control set for maximum cold, airflow across the A/C evaporator core will be diverted past the heater core and then directed into the passenger compartment through the instrument panel A/C registers.
^ The A/C compressor will be operating.
^ The blower motor is on.







A/C
When A/C is selected:
^ The A/C damper inlet door is set at no vacuum, blocking the recirculation passage and admitting outside air.
^ The heater air damper door is at full vacuum, directing airflow to the instrument panel A/C registers.
^ The windshield defroster door is at full vacuum, closing off airflow to the windshield defroster hose nozzles.
^ The temperature setting can be selected manually.
^ The A/C compressor will be operating when A/C button is depressed.
^ The blower motor is on.







PANEL
When PANEL is selected:
^ The A/C damper inlet 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 heater air damper door control motor controls airflow across the heater core.
^ The windshield defroster door is at full vacuum, closing off airflow to the windshield defroster hose nozzles.
^ The temperature setting can be selected manually to heat the air but air cannot be cooled below outside temperature,
^ A/C is not selected.
^ The blower motor is on.







PANEL/FLOOR
When PANEL/FLOOR is selected:
^ The A/C damper inlet door is set at no vacuum, blocking the recirculated passage and admitting outside air.
^ The heater air damper door is in the partial vacuum position, allowing airflow to both heater outlet floor duct and the instrument panel A/C registers.
^ The windshield defroster door is at full vacuum, closing off airflow to the windshield defroster hose nozzles.
^ The temperature setting can be selected manually to heat the air but to cool the air the A/C request button must be depressed.
^ The blower motor is on.







OFF
When OFF is selected:
^ The A/C damper inlet door is at full vacuum. As a result, outside air is closed off and recirculated air is admitted to the system.
^ The windshield defroster door is at full vacuum and the heater air damper door is at no vacuum, closing off the airflow to the windshield defroster hose nozzle.
^ The blower motor and the A/C compressor are off.







FLOOR
When FLOOR is selected:
^ The A/C damper inlet door is in the no vacuum position, blocking recirc air and admitting outside air.
^ The heater air damper door is in the no vacuum position, closing off airflow to the panel A/C registers.
^ The air temperature control door may be positioned to mix air flowing through and around the heater core to achieve the desired temperature level.
^ The windshield defroster door is in the full vacuum position, closing off all but a minimum of airflow to the windshield defroster hose nozzle.
^ The air can be cooled if the A/C request button is depressed.
^ The blower motor is on.







MIX
When the MIX is selected:
^ The A/C damper inlet door is in the no vacuum position.
^ The heater air damper door is in the no vacuum position, allowing no airflow to instrument panel A/C registers.
^ The windshield defroster door is in the partial vacuum position, allowing airflow to both heater outlet floor duct and windshield defroster hose nozzles.
^ The A/C compressor operates to dehumidify the air and reduce windshield fogging.







DEFROST
When DEFROST is selected:
^ The A/C damper inlet door is in the no vacuum position, admitting outside air.
^ The heater air damper door is in the no vacuum position blocking airflow to the instrument panel A/C registers.
^ The windshield defroster door is in the no vacuum position, so that most of the incoming air is directed to the windshield defroster hose nozzles.
^ The temperature control knob 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 operates to dehumidify the air and reduce windshield fogging.
^ The blower motor is on.