Auxiliary Climate Control

AUXILIARY CLIMATE CONTROL

An optional auxiliary climate control system is available. The system is a one-piece unit that is located on the RH 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.

System Airflow

System Airflow:

The auxiliary A/C and heating system has the following features:
- The auxiliary climate control system is functional whenever the instrument panel mounted HVAC module is in any mode except OFF.
- The auxiliary blower motor recirculates the air inside the vehicle. Outside air is not available to the auxiliary system.
- Air is cooled and dehumidified by the auxiliary A/C evaporator core only if the front (main) climate control system is operating in a mode that requires A/C compressor operation.
- The temperature blend door and the auxiliary mode door are controlled by electric 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.
- Movement of the auxiliary mode control between PANEL and FLOOR causes a corresponding movement of the auxiliary mode door to direct airflow between the panel (headliner) registers and the floor duct.

Blower Motor
The auxiliary climate control system is equipped with a blower motor controlled by the blower motor switch on the front or rear auxiliary control assembly. The auxiliary blower motor is mounted to the auxiliary heater core and evaporator core housing behind the RH quarter trim panel.

Control Assembly
The auxiliary climate control system has dual controls for the front and rear passengers consisting of temperature/mode and blower speed. The front auxiliary A/C control functionality is integrated into the main instrument panel mounted HVAC module. The rear auxiliary A/C control is mounted in the rear finish panel of the front floor console. Temperature and airflow mode are combined into a single setting. When the temperature is set to full cool the airflow mode will be automatically set to discharge from the headliner registers. When the temperature is set to full warm, the airflow mode will be set to discharge from the floor register.

Heater Core
The heater core consists of fins and tubes arranged to extract heat from the engine coolant and transfer the heat to air passing through the auxiliary climate control housing.

Evaporator Core

NOTE:
- If an evaporator core leak is suspected, the evaporator core must be vacuum leak tested before it is removed from the vehicle.
- Installation of a new receiver/drier cartridge is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the receiver/drier cartridge.

The evaporator core is an aluminum plate/fin type and is located in the auxiliary climate control housing. A mixture of refrigerant and oil enters the bottom of the evaporator core through the evaporator core inlet tube and then moves out of the evaporator core through the evaporator core outlet tube. When the A/C compressor is operating, air from the blower motor is cooled and dehumidified as it flows through the evaporator core fins.

Thermostatic Expansion Valve (TXV)
The TXV restricts the flow of refrigerant from the high-pressure side of the refrigerant system and separates the low-pressure and high-pressure sides of the auxiliary refrigerant system. Refrigerant entering and exiting the auxiliary evaporator core passes through the TXV through 2 separate flow paths. An internal temperature sensing bulb senses the temperature of the refrigerant flowing out of the evaporator core and adjusts an internal pin-type valve to meter the refrigerant flow into the evaporator core. The internal pin-type valve decreases the amount of refrigerant entering the evaporator core at lower temperatures and increases the amount of refrigerant entering the evaporator core at higher temperatures.

Auxiliary A/C - Heater Lines
The auxiliary lines are secured to the underbody of the vehicle. Each auxiliary line is only available as a multiple-piece kit for ease of installation.