Auxiliary Climate Control

AUXILIARY CLIMATE CONTROL

Air Conditioning - Auxiliary

Component Location:

Component Location

A/C Lines And Heater Tubes - Vehicle Underbody, Vans Except RV:

A/C Lines And Heater Tubes - Vehicle Underbody, Vans Except RV

A/C Lines And Heater Tubes - Vehicle Underbody, Vans And Cutaways:

A/C Lines And Heater Tubes - Vehicle Underbody, Vans And Cutaways

An optional auxiliary air conditioning and heating system is available on these vehicles. The system is a one-piece unit that is located on the LH side of the vehicle between the side windows and the Floorpan, behind the rear wheel well. The auxiliary air conditioning and heating system can also be equipped with an optional blower motor switch, mounted in the rear of the vehicle.

All of the auxiliary A/C-heater system components are serviceable from the inside of vehicle.

Air Distribution
Vehicles with trim have a vertical duct that supplies air to the integral headliner air conditioning duct. Air is supplied to the passengers through six adjustable registers. The heater floor duct is integral to the side trim panel and has four fixed registers for optimum heater air distribution. The trim panel connects directly to the auxiliary A/C-heater unit.

Vehicles without trim do not have the overhead A/C registers, heater floor ducts or registers. A unique A/C register is used to distribute air-conditioned air, and a heater outlet duct assembly distributes heated air.

System Airflow
The A/C-heater function selector switch (located in the front A/C control) controls the air distribution for both the front and auxiliary systems.
^ When the A/C-heater function selector switch is in the VENT, FLOOR or MIX position, the auxiliary A/C-heater system will direct air to the floor. The damper door is driven by a vacuum control motor to its predetermined position.
^ When the A/C-heater function selector switch is in the VENT position, the auxiliary A/C-heater unit will be in a recirculating function and will deliver interior air to the discharge registers.
^ When the A/C-heater function selector switch is in the NORM A/C or MAX A/C position, air-conditioned air is distributed through the A/C registers.

Blower Motor
The auxiliary air conditioning and heating assembly contains a blower motor. It is controlled by the heater blower motor switch on the front or rear auxiliary A/C control.

Control Assembly
The auxiliary A/C-heater system has an optional rear climate control assembly, mounted in the headliner in the rear of the vehicle. This control assembly has the same settings as the heater blower motor switch (located on the A/C control). These switches allow the auxiliary blower motor to be turned off while the main blower motor is operating. By placing the heater blower motor switch in the REAR CONTROL position, the auxiliary blower motor can then be controlled from the rear climate control panel.

Heater Core
The auxiliary A/C system uses a rear-mounted heater core which operates in the same manner as the front mounted heater core.

A/C Evaporator Core
The auxiliary A/C system uses a rear-mounted A/C evaporator core which operates in the same manner as the front mounted A/C evaporator core.

Thermostatic Expansion Valve

Thermostatic Expansion Valve:

An A/C evaporator expansion valve regulates the flow of refrigerant into the auxiliary A/C evaporator core. It is also the dividing point in the system between low- and high-pressure sides.

The temperature sensing bulb measures the temperature of the refrigerant in the suction line and transmits it to the A/C evaporator expansion valve. This temperature variation regulates the refrigerant flow to the auxiliary A/C evaporator core.
^ When the bulb senses a high temperature, the A/C evaporator expansion valve opens and provides refrigerant through the auxiliary A/C evaporator core.
^ When the bulb senses a low temperature, the A/C evaporator expansion valve starts closing to shut off the refrigerant to the auxiliary A/C evaporator core.