Ford 2003 Mustang Workshop Manual page 3156

SECTION 412-02: Heating and Ventilation
DESCRIPTION AND OPERATION
Heating and Defrosting
The heating and defrosting system has the following features:
Controls the temperature and, during A/C operation, reduces the relative humidity of the air
inside the vehicle.
Delivers heated or cooled air to maintain the vehicle interior temperature and comfort level.
Controls the A/C blower motor speed.
Cooling or heating can be adjusted to maintain the desired temperature.
System uses a reheat method to provide conditioned air to the passenger compartment.
The blower motor (19805) draws outside air through the air inlet duct from just below the
windshield during all system operations except for MAX A/C cooling (when recirculated air is
used).
All airflow from the blower motor passes through the A/C evaporator core (19860).
The temperature is then regulated by reheating a portion of the air and blending it with the
remaining cool air to the desired temperature.
The temperature blending is varied by the air temperature control door, which regulates the
amount of air that flows through and around the heater core (18476), where it is then mixed and
distributed.
Heater Core
The heater core (18476) consists of fins and tubes arranged to extract heat from the engine coolant
and transfer it to air passing through the heater core.
Blower Motor
2003 Mustang Workshop Manual