Auxiliary Climate Control

THERMOSTATIC EXPANSION VALVE

NOTE: An in-line filter is installed in the auxiliary evaporator inlet jumper line at the underbody peanut fitting near the floorpan line bracket. A restriction in this filter may cause misdiagnosis of a failed thermostatic expansion valve. Before a new thermostatic expansion valve is installed, this filter must be inspected and in the event of an internal compressor desiccant failure, a new filter must be installed.

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.