Chrysler 2000 LHS - Evaporator Temperature Sensor Setpoint; Filter-Drier; Handling Tubing and Fittings

OPERATION
High-pressure, high temperature liquid refrigerant
from the liquid line passes through the expansion
valve orifice, converting it into a low-pressure, low-
temperature mixture of liquid and gas before it
enters the evaporator coil. A temperature sensor in
the expansion valve control head monitors the tem-
perature of the refrigerant leaving the evaporator coil
through the suction line, and adjusts the orifice size
at the liquid line to let the proper amount of refrig-
erant into the evaporator coil to meet the vehicle
cooling requirements. Controlling the refrigerant flow
through the evaporator ensures that none of the
refrigerant leaving the evaporator is still in a liquid
state, which could damage the compressor.
FILTER-DRIER
DESCRIPTION
The filter-drier is located in the engine compart-
ment near the dash panel on the passenger side of
the vehicle. The filter-drier incorporates a sight glass
for visual diagnosis of the refrigerant system
OPERATION
High-pressure liquid refrigerant from the con-
denser flows into the filter-drier. A drying agent,
called a desiccant, is used to remove any traces of
moisture from the refrigerant system. The filter-drier
also performs a filtering action to prevent foreign
material in the refrigerant from contaminating the
expansion valve. In addition, during periods of high
demand air conditioner operation, the filter-drier acts
as a reservoir to store surplus refrigerant.
The A/C refrigerant must be removed from the sys-
tem before removing the filter/drier using a refriger-
ant recovery machine. Replace the filter/drier if an
A/C system is left open for an extended period of
time.
The filter-drier cannot be repaired and, if faulty,
must be replaced.
HANDLING TUBING AND FITTINGS
DESCRIPTION
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system.
EVAPORATOR TEMPERATURE SENSOR
SETPOINT
AMBIENT
TEMPERATURE
SENSOR READING ° F
(° C)
A/C CLUTCH OFF
EVAPORATOR
TEMPERATURE
SETPOINT ° F (° C)
185 (85) 31 (-.5)
100 (37.7) 31 (-.5)
77 (25) 34 (1.1)
60 (15.5) 35 (1.6)
-70 (-56.6) 36 (2.2)
Fig. 2 Evaporator Temperature Sensor Setpoint
24 - 4 HEATING AND AIR CONDITIONING LH
DESCRIPTION AND OPERATION (Continued)