LTD Crown Victoria V8-302 5.0L VIN F FI (1986)
Control Assembly: Description and Operation
With Air Conditioning
DESCRIPTION AND OPERATION
Manual A/C Heater Control Functions
The manual A/C-heater control includes a function control lever for Off, Max-A/C, Norm-A/C, Vent, Floor, Defog (Mix), Defrost that determines the
manner in which the system will operate, a temperature control lever for manually setting the desired comfort temperature and a blower switch to control
the volume of air movement. Each position of the function control lever and blower switch is detented for positive engagement. The blower switch
provides four manually selected blower speeds and may be operated in any position to select the desired amount of airflow.
Temperature Control
Temperature control of the manual A/C heater system is determined by the position of the temperature control lever (between COOL and WARM)
of the control assembly and is accomplished by means of a control cable between the control assembly and the temperature blend door. System
airflow is manually controlled by the control assembly. A vacuum selector valve, controlled by the function control lever, distributes vacuum to
the various door vacuum motors which in turn direct the airflow through the system.
The system utilizes what is called a reheat method to provide conditioned air to the vehicle interior. With this method, all airflow from the blower
passes through the evaporator core, where it is cooled and dehumidified.
Temperature is then regulated by reheating a portion of the cooled dry air and blending it with the remaining cool air to the desired temperature.
Temperature blending is varied by the temperature blend door which controls the amount of cooled air that flows through or around the heater core
, where it is mixed and directed into the distribution plenum. The air is finally directed to the heater ducts, the defroster nozzles, or the instrument
panel registers according to the selected function lever position.
