Dodge 2000 DURANGO Service Manual page 942

24 - 12 HEATING AND AIR CONDITIONING
DIAGNOSIS AND TESTING (Continued)
Review the Service Warnings and Precautions in
the General Information section near the front of this
group before performing this procedure. The air tem-
perature in the test room and in the vehicle must be
a minimum of 21° C (70° F) for this test.
(1) Connect a tachometer and a manifold gauge
set.
(2) Set the heater-A/C mode control switch knob in
the recirculation mode (Max-A/C) position, the tem-
perature control knob in the full cool position, and
the blower motor switch knob in the highest speed
position.
(3) Start the engine and hold the idle at 1,000 rpm
with the compressor clutch engaged. If the compres-
sor clutch does not engage, see the A/C Diagnosis
chart in the Diagnosis and Testing section of this
group.
(4) The engine should be at operating temperature.
The doors and windows must be closed and the hood
must be mostly closed.
CAUTION: Never insert a thermometer probe into
the outlet for the optional rear overhead A/C unit.
Failure to observe this caution could result in dam-
age to the rear blower wheel and/or the thermome-
ter.
(5) Insert a thermometer in the driver side center
A/C (panel) outlet for testing of the front unit, or
hold a thermometer near the center outlets in the
Ambient Temperature
Maximum Allowable Air
Temperature at Left Center
Panel Outlet
Compressor Inlet Pressure
(Low Side)
Condenser Out Pressure at
Service Port (High Side)
(8) Compare the discharge (high side) and suction
(low side) pressure readings to the Performance Tem-
perature and Pressure chart. If the pressures are
Performance Temperature and Pressure
21°C 27°C
(70°F) (80°F)
9°C 9°C
(48°F) (48°F)
138 to 207 138 to 207
kPa kPa
(20 to 30 psi) (20 to 30 psi)
689 to 1034 931 to 1276
kPa kPa
(100 to 150 (135 to 185
psi) psi)
headliner for testing of the rear unit. Operate the
engine for five minutes.
(6) With the compressor clutch engaged, record the
panel outlet or left center outlet discharge air tem-
perature, the condenser out pressure (high side), and
the compressor inlet pressure (low side). The com-
pressor clutch may cycle, depending upon the ambi-
ent temperature and humidity. If the clutch cycles,
use the readings obtained before the clutch disen-
gaged.
(7) Compare the discharge air temperature read-
ing to the Performance Temperature and Pressure
chart. If the temperature reading is high for the rear
unit, see Refrigerant System Leaks in the Diagnosis
and Testing section of this group, and Refrigerant
System Charge in the Service Procedures section of
this group. If the temperature reading is high for the
front unit, clamp off both heater hoses (inlet and out-
let), wait five minutes and record the temperature
again. Compare the second reading to the Perfor-
mance Temperature and Pressure chart. If the tem-
perature reading is now OK, see Temperature
Control Cable in the Removal and Installation sec-
tion and in the Adjustments section of this group. If
the temperature reading is still too high, see Refrig-
erant System Leaks in the Diagnosis and Testing sec-
tion of this group, and Refrigerant System Charge in
the Service Procedures section of this group.
32°C
(90°F)
12°C
(54°F)
172 to 241
kPa
(25 to 35 psi)
1172 to 1517
kPa
(170 to 220
psi)
abnormal, suction pressure is not normal, see the A/C
Diagnosis chart in the Diagnosis and Testing section
of this group.
38°C 43°C
(100°F) (110°F)
15°C 18°C
(59°F) (65°F)
214 to 283 255 to 324
kPa kPa
(31 to 41 psi) (37 to 47 psi)
1448 to 1758 1689 to 2034
kPa kPa
(210 to 255 (245 to 295
psi) psi)
DN