Durango 2WD V8-5.7L (2008)
Housing Assembly HVAC: Description and Operation
Rear
DESCRIPTION
Models equipped with the rear heating-A/C system are equipped with a common rear heater and A/C housing (7) that combines A/C and heating
capabilities into a single unit mounted within the passenger compartment. The rear heating-A/C system is a blend-air type system. A blend-air door (6)
controls the amount of conditioned air that is allowed to flow through, or around, the heater core (3). The rear A/C system is designed for the use of a
non-CFC, R-134a refrigerant and uses an A/C evaporator (2) to cool and dehumidify the incoming air prior to blending it with the heated air. A
temperature control determines the discharge air temperature by operating the blend door actuator (5), which moves the blend-air door. This allows an
almost immediate control of the output air temperature of the system. The mode door actuator (8) operates the mode-air door (9) which directs the flow
of the conditioned air out the upper or lower air outlets, depending on the discharge air temperature selected. Both electric actuators are connected to the
vehicle electrical system by the HVAC wire harness (10). The rear blower motor (11) controls the velocity of air flowing through the rear HVAC
housing by spinning the blower wheel within the rear blower motor housing (1) at the selected speed by use of the rear blower motor resistor block (4).
The rear HVAC housing must be removed from the vehicle and disassembled for service of the A/C evaporator, heater core, mode-air door, blend-air
door and blower motor.
