Ford Mustang (1999-2004) Service Manual: System Air Flow Description

MAX A/C

When MAX A/C is selected:

• The air inlet door vacuum control motor is at full vacuum, closing off outside air and admitting only recirculated air.
• The panel/defrost door vacuum control motor is at full vacuum and the panel/floor door vacuum control motor is at no vacuum, directing airflow to the instrument panel A/C registers. A small amount of airflow from the side window demisters will be present.
• Blended air temperature is available.
• The A/C compressor will operate if the outside temperature is above approximately 6C (43F).
• The blower motor is on.

NORM A/C

When NORM A/C is selected:

• The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
• The panel/defrost door vacuum control motor is at full vacuum and the panel/floor door vacuum control motor is at no vacuum, directing airflow to the instrument panel A/C registers. A small amount of airflow from the side window demisters will be present.
• Blended air temperature is available.
• The A/C compressor will operate if the outside air temperature is above approximately 6C (43 F).
• The blower motor is on.

PANEL

When PANEL is selected:

• The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
• The panel/defrost door vacuum control motor is at full vacuum and the panel/floor door vacuum control motor is at no vacuum, directing airflow to the instrument panel A/C registers. A small amount of airflow from the side window demisters will be present.
• The temperature can be adjusted to heat the air, but the air cannot be cooled below the outside temperature.
• The A/C compressor will not operate.
• The blower motor is on.

OFF

When OFF is selected:

• The air inlet door vacuum control motor is at full vacuum, closing off outside air from entering the passenger compartment.
• The panel/floor door vacuum control motor is at full vacuum and the panel/defrost door vacuum control motor is at no vacuum, closing off airflow to the defrost duct, side window demisters, floor duct and instrument panel A/C registers.
• The A/C compressor will not operate.
• The blower motor is off.

FLOOR

When FLOOR is selected:

• The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
• The panel/floor door vacuum control motor is at full vacuum and the panel/defrost door vacuum control motor is at no vacuum, directing airflow to the floor duct. A small amount of airflow from the side window demisters will be present.
• The temperature can be adjusted to heat the air, but the air cannot be cooled below the outside temperature.
• The A/C compressor will not operate.
• The blower motor is on.

FLOOR/DEFROST

When FLOOR/DEFROST is selected:

• The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
• The panel/floor door vacuum control motor is at partial vacuum and the panel/defrost door vacuum control motor is at no vacuum, directing airflow to the floor duct, the defroster duct, and the side window demisters.
• The temperature can be adjusted to heat or cool the air below the outside temperature.
• The A/C compressor will operate if the outside air temperature is above approximately 6C (43 F).
• The blower motor is on.

DEFROST

When DEFROST is selected:

• The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
• The panel/floor door and panel/defrost door vacuum control motors are at no vacuum, directing airflow to the defroster duct and the side window demisters.
• The temperature can be adjusted to heat or cool the air below the outside temperature.
• The A/C compressor will operate if the outside air temperature is above approximately 6C (43 F).
• The blower motor is on.

Electrical Components