Dodge ZB 2005, Руководство по обслуживанию

Страница: 1032 / 1873

perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and coils. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause of
trouble with the A/C system. The ambient air tem-
perature in the location where the vehicle will be
tested must be a minimum of 21° C (70° F) for this
test.
A/C PERFORMANCE TEST
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
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
or a A/C Charging/Recycling Station.
(2) Set the A/C-heater control to the Recirculation
mode (max-A/C) position, the temperature control to
the full cool position, and the blower motor control to
the highest speed position.
(3) Start the engine and hold the idle at 1,000 rpm
with the compressor clutch engaged. If the A/C com-
pressor does not engage, see the A/C Diagnosis chart.
(4) The engine should be at operating temperature,
the doors should be closed and the windows opened.
(5) Insert a thermometer in the driver side center
panel outlet. Operate the A/C system until it stabi-
lizes.
(6) With the A/C compressor clutch engaged, com-
pare the air temperature at the center panel outlet
and the A/C compressor discharge pressure (high
side) to the A/C Performance and Pressure chart. The
compressor clutch may cycle, depending upon the
ambient temperature and humidity. If the clutch
cycles, use the readings obtained before the clutch
disengaged.
A/C PERFORMANCE TEMPERATURE AND PRESSURE
Ambient Air Temperature 16°C
(60°F)
21°C
(70°F)
27°C
(80°F)
32°C
(90°F)
38°C
(100°F)
Maximum Allowable Air Tem-
perature at Center Panel Out-
let
7°C
(45°F)
7°C
(45°F)
13°C
(55°F)
13°C
(55°F)
18°C
(64°F)
Compressor Suction Pressure
(Low Side) 138 to 207
kPa
(20 to 30
psi)
172 to 241
kPa
(25 to 35
psi)
207 to 276
kPa
(30 to 40
psi)
241 to 310
kPa
(35 to 45
psi)
276 to 345
kPa
(40 to 50
psi)
Compressor Discharge Pres-
sure (High Side) 1034 to
1724 kPa
(150 to 250
psi)
1379 to
2068 kPa
(200 to 300
psi)
1724 to
2413 kPa
(250 to 350
psi)
1999 to
2689 kPa
(290 to 390
psi)
2413 to 2965
kPa
(350 to 430
psi)
(7) If the air outlet temperature fails to meet the
specifications in the A/C Performance Temperature
and Pressure chart, or if the A/C compressor dis-
charge pressure is high, refer to the A/C Pressure
Diagnosis chart.
ZB
HEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)