Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
Vehicle » Heating and Air Conditioning » Description and Operation » Heating and Defrosting  
  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.
  • Cooling or heating can then be adjusted to maintain the desired temperature.
  • System uses a reheat method to provide conditioned air to the passenger compartment.
  • The blower motor 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 housing.
  • 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 in the heater core housing, where it is then mixed and distributed.

Heater Core Housing
The heater core housing contains the following components:

  • heater core
  • air temperature control door
  • panel airflow control door
  • defrost/floor airflow control door

Of these components, only the heater core is serviceable. If any of the airflow control components are not working, a new heater core housing must be installed.


Heater Core
The heater core consists of fins and tubes arranged to extract heat from the engine coolant and transfer the heat to air passing through the heater core housing.


Blower Motor
The blower motor pulls air from the air inlet and forces it into the heater core housing where it is mixed and distributed.