Chrysler 1998 Voyager Service Manual page 1828

24 - 12 HEATING AND AIR CONDITIONING
DIAGNOSIS AND TESTING (Continued)
probe will drop the temperature 7°C (20°F) in two
minutes. If the Evaporator Probe is found to be
faulty, check that the sensor is positioned in the
evaporator fins properly. If not, correct and repeat
test. If OK, replace the evaporator probe.
Once the repairs are completed, repeat the Calibra-
tion Diagnostic and Cooldown test. Repeating the
test is necessary to clear the fault codes.
A/C PERFORMANCE TEST
The air conditioning system is designed to remove
heat and humidity from the air entering the passen-
ger compartment. The evaporator, located in the
heater A/C unit, is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins in the evaporator, moisture in the air condenses
to water, dehumidifying the air. Condensation on the
evaporator fins reduces the evaporators ability to
absorb heat. During periods of high heat and humid-
ity, an air conditioning system will be less effective.
With the instrument control set to RECIRC, only air
from the passenger compartment passes through the
evaporator. As the passenger compartment air dehu-
midifies, A/C performance levels rise.
PERFORMANCE TEST PROCEDURE
Review Safety Precautions and Warnings in this
group before proceeding with this procedure. Air tem-
perature in test room and on vehicle must be 21° C
(70°F) minimum for this test.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a tachometer and manifold gauge set.
(2) Set control to A/C, RECIRC, and PANEL, tem-
perature lever on full cool and blower on high.
(3) Start engine and hold at 1000 rpm with A/C
clutch engaged.
AMBIENT TEMPERATURE
AIR TEMPERATURE AT LEFT
CENTER PANEL OUTLET
COMPRESSOR DISCHARGE
PRESSURE AFTER THE FILTER
DRIER
EVAPORATOR SUCTION
PRESSURE
A/C PERFORMANCE TEMPERATURES
21°C 26.5°C
(70°F) (80°F)
1-8°C 3-9°C
(34-46°F) (37-49°F)
1034-1724 1517-2275
kPa
(150-250 (220-330
PSI) PSI)
103-207 kPa 117-221 kPa
(15-30 PSI) (17-32 psi)
(4) Engine should be warmed up with doors and
windows closed.
(5) Insert a thermometer in the left center A/C
outlet and operate the engine for five minutes. The
A/C clutch may cycle depending on ambient condi-
tions.
(6) With the A/C clutch engaged, compare the dis-
charge air temperature to the A/C Performance Tem-
peratures table.
(7) If the discharge air temperature fails to meet
the specifications in the performance temperature
chart. Refer to the Refrigerant Service Procedures for
further diagnosis.
A/C PRESSURE TRANSDUCER
The work area temperature must not be below
10°C (50°F) to test the compressor clutch circuit.
Before starting to test the transducer ensure that the
wire connector is clean of corrosion and connected
properly.
(1) With gear selector in park or neutral and park
brake set, start engine and allow to idle.
(2) Install scan tool (DRB):
• Go to main menu
• Select stand alone scan tool (DRB)
• Select refer to the proper year diagnostics
• Select climate control
• Select sensor display
• Select A/C high side volts
For A/C system to operate a voltage between .451
(Low Pressure Cutout) to 4.519 (High Pressure Cut-
out is required. Voltages outside this range indicate a
low or high pressure condition and will not allow
the compressor to cycle.
Refer to the A/C Pressure Transducer Voltage table
for the appropriate condition(s):
32°C
(90°F)
4-10°C
(39-50°F)
1999-2620
kPa kPa
(290-380
PSI)
138-241 kPa
(20-35 PSI)
37°C 43°C
(100°F) (110°F)
6-11°C 7-18°C
(43-52°F) (45-65°F)
2068-2965 2275-3421
kPa kPa
(300-430 (330-496
PSI) PSI)
172-269 kPa 207-345 kPa
(25-39 PSI) (30-50 PSI)
NS