Air Conditioning System

AUXILIARY CLIMATE CONTROL
An optional auxiliary air conditioning and heating system is available on the Econoline vehicles. The auxiliary climate control housing is located on the LH side of the vehicle between the side windows and the floorpan, behind the rear wheel well.

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 overhead 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 function selector switch (located in the front A/C control controls the air distribution for both the front and auxiliary systems.
- The mode door is driven by a vacuum control motor to its predetermined position.
- When the function selector switch is in the FLOOR or MIX position, the auxiliary system will direct air to the floor.
- When the function selector switch is in the VENT position, the auxiliary system will direct air to the overhead vents.
- When the function selector switch is in the NORM A/C or MAX A/C position, air-conditioned air is distributed through the A/C registers.
- The auxiliary system uses only recirculated air from the vehicle interior. Outside air intake is not available.

Blower Motor
The auxiliary climate control assembly contains a blower motor. It is controlled by the heater blower motor switch on the front climate control assembly.

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
A thermostatic expansion valve (TXV) 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 TXV. This temperature variation regulates the refrigerant flow to the auxiliary A/C evaporator core.
- When the bulb senses a high temperature, the TXV opens and provides refrigerant through the auxiliary A/C evaporator core.
- When the bulb senses a low temperature, the TXV starts closing to shut off the refrigerant to the auxiliary A/C evaporator core.