Auxiliary Climate Control

AUXILIARY CLIMATE CONTROL

Auxiliary Climate Control
The auxiliary climate control 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 driver has primary control of the auxiliary climate control system or can transfer control to a rear passenger control panel.

All of the auxiliary climate control system components are serviceable from the inside of the vehicle except the lines.

Auxiliary System Air Distribution
A vertical air distribution duct supplies air to the integral headliner air distribution duct. Airflow is then directed to the passengers through adjustable registers. The heater floor duct supplies air to a fixed register which is integral to the side trim panel and directs airflow through the fixed register to the passenger compartment.

System Airflow:

The auxiliary climate control system has the following features:
- The auxiliary blower motor recirculates the air inside the vehicle. Outside air is not available to the auxiliary climate control system.
- Air is cooled and dehumidified by the auxiliary evaporator core only if the instrument panel mounted climate control assembly is adjusted to a position that requires A/C compressor operation.
- The temperature blend door and the air distribution door are controlled by electronic actuator motors.
- Movement of the auxiliary temperature control between COOL and WARM causes a corresponding movement of the temperature blend door to mix air flowing through and around the auxiliary heater core.
- Toggling of the auxiliary air distribution control between PANEL and FLOOR causes a corresponding movement of the air distribution door to direct airflow between the panel (headliner) registers and the floor duct.

Blower Motor
The auxiliary climate control system contains a blower motor which is controlled by the blower motor switch on the front or rear auxiliary climate control assembly.

Control Assembly
The auxiliary climate control system has dual controls for the driver and rear passengers consisting of temperature, blower speed and air distribution mode. The front auxiliary climate control assembly is mounted in the overhead console. The rear auxiliary climate control assembly is mounted in a separate overhead console positioned on the headliner above the second row seating area.

Heater Core
The auxiliary climate control system uses a rear heater core which operates in the same manner as the front heater core.

Evaporator Core

NOTE: The auxiliary evaporator core is not installed separately. It is installed only with the auxiliary climate control housing.

The auxiliary climate control system uses a rear evaporator core which operates in the same manner as the front evaporator core.

Thermostatic Expansion Valve
A thermostatic expansion valve automatically regulates the flow of refrigerant into the auxiliary 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 thermostatic expansion valve. This temperature variation regulates the refrigerant flow to the auxiliary evaporator core.
- When the bulb senses a high temperature, the thermostatic expansion valve opens and floods refrigerant through the auxiliary evaporator core.
- When the bulb senses a low temperature, the thermostatic expansion valve starts closing to shut off the refrigerant to the auxiliary evaporator core.

Underbody Auxiliary A/C Lines
The underbody auxiliary A/C lines carry refrigerant to the auxiliary A/C evaporator inlet line, and away from the auxiliary A/C evaporator outlet line. The auxiliary underbody lines have the following characteristics.
- The underbody auxiliary A/C evaporator inlet line consists of 2 separately installed pieces.
- The fore auxiliary A/C evaporator inlet line carries high pressure refrigerant liquid from the condenser to evaporator line to the aft auxiliary A/C evaporator inlet line.
- The aft auxiliary A/C evaporator inlet line carries high pressure refrigerant liquid from the fore auxiliary A/C evaporator inlet line to the auxiliary evaporator inlet.
- The underbody auxiliary A/C evaporator outlet line consists of 2 separately installed pieces.
- The aft auxiliary A/C evaporator outlet line carries refrigerant vapor from the auxiliary A/C evaporator outlet to the fore auxiliary A/C evaporator outlet line.
- The fore auxiliary A/C evaporator outlet line carries refrigerant vapor from the aft auxiliary A/C evaporator inlet line to the manifold and tube assembly.

Underbody Heater Lines
The underbody auxiliary heater lines have the following features.
- The underbody auxiliary heater inlet line consists of 2 separately installed assemblies.
- The fore underbody auxiliary heater inlet line is a steel tube assembly that carries coolant from the front heater core inlet line to the aft underbody auxiliary heater inlet line.
- The aft underbody auxiliary heater inlet line carries coolant from the fore underbody heater inlet line to the auxiliary heater core.
- The aft underbody auxiliary heater inlet line consists of a steel tube with formed rubber hoses at each end. The rubber hoses are attached and sealed to the tube using constant tension pop clamps.
- The aft underbody auxiliary heater outlet line carries coolant from the auxiliary heater core to the fore underbody auxiliary heater outlet line.
- The aft underbody auxiliary heater outlet line consists of a steel tube with formed rubber hoses at each end. The rubber hoses are attached and sealed to the tube using constant tension pop clamps.
- The fore underbody auxiliary heater outlet line is a steel tube assembly that carries coolant from the aft underbody heater outlet line to the front heater core outlet line.