Function Control Knob
When function control knob is in PANEL position, air inlet door vacuum control motor is at no vacuum, admitting only outside air into passenger compartment. See Fig 1. Floor/defrost door and panel/floor door vacuum control motors are at full vacuum, directing airflow to instrument panel registers. Temperature can be adjusted to heat air. Blower motor is on.
When function control knob is in OFF position, air inlet door vacuum control motor is at full vacuum, closing off outside air from entering passenger compartment. See Fig 2. Floor/defrost door vacuum control motor is at full vacuum and panel/floor door vacuum control motor is at no vacuum, closing off airflow to defrost duct, side window demisters, floor duct and instrument panel registers. Blower motor is off.
When function control knob is in PANEL/FLOOR position, air inlet door vacuum control motor is at no vacuum, admitting only outside air into passenger compartment. See Fig 3. Floor/defrost door vacuum control motor is at full vacuum and panel/floor door vacuum control motor is at partial vacuum, directing airflow to floor duct and instrument panel registers. Blower motor is on.
When function control knob is in FLOOR position, air inlet door vacuum control motor is at no vacuum, admitting only outside air into passenger compartment. See Fig 4. Floor/defrost door vacuum control motor is at full vacuum and panel/floor door vacuum control motor is at no vacuum, directing airflow to floor duct. Temperature can be adjusted to heat air. Blower motor is on.
When function control knob is in FLOOR/DEFROST position, air inlet door vacuum control motor is at no vacuum, admitting only outside air into passenger compartment. See Fig 5. Floor/defrost door vacuum control motor is at partial vacuum and panel/floor door vacuum control motor is at no vacuum, directing airflow to floor duct, defroster duct and side window demisters. Temperature can be adjusted to heat air. Blower motor is on.
When function control knob is in DEFROST position, air inlet door vacuum control motor is at no vacuum, admitting only outside air into passenger compartment. See Fig 6. Panel/floor door and floor/defrost door vacuum control motors are at no vacuum, directing airflow to defroster duct and side window demisters. Temperature can be adjusted to heat air. Blower motor is on.