gage panel DODGE RAM 1500 1998 2.G Repair Manual

SEAT CUSHION / COVER -
FRONT
REMOVAL
(1) Remove the front seat. (Refer to 23 - BODY/
SEATS/SEAT - FRONT - REMOVAL)
(2) Remove the screw and remove the recliner han-
dle.
(3) Remove the two screws and remove the power
seat controls, if equipped, and disconnect the electri-
cal connector.
(4) Remove the seat track. (Refer to 23 - BODY/
SEATS/SEAT TRACK - REMOVAL)
(5) Disconnect the j-straps and remove the seat
cushion and cover.
INSTALLATION
(1) Position the seat cushion and cover onto the
frame assembly and connect the j-straps.
(2) Install the seat track. (Refer to 23 - BODY/
SEATS/SEAT TRACK - INSTALLATION)
(3) Connect the power seat control switch electrical
connector, if equipped.
(4) Install the power seat control switch and
install the two screws, if equipped.
(5) Install the recliner handle and install the
screw.
(6) Install the front seat. (Refer to 23 - BODY/
SEATS/SEAT - FRONT - INSTALLATION)
SEAT TRACK
REMOVAL
(1) Remove the front seat. (Refer to 23 - BODY/
SEATS/SEAT - FRONT - REMOVAL)
(2) Disconnect the heated seat electrical connec-
tors, if equipped.
(3) Remove the four nuts attaching the seat track
to the seat and remove the track.
INSTALLATION
(1) Position the seat track onto the seat and install
the four nuts.
(2) Tighten the four nuts to 25 N´m (18 ft. lbs.).
(3) Connect the heated seat electrical connectors, if
equipped.
(4) Install the seat. (Refer to 23 - BODY/SEATS/
SEAT - FRONT - INSTALLATION)
SEAT - REAR
REMOVAL
(1) Remove the load floor. (Refer to 23 - BODY/IN-
TERIOR/LOAD FLOOR - REMOVAL)
(2) Fold the rear seat cushions up and remove the
rear bolts. (Fig. 17)
(3) Lift each seat assembly up and disengage the
seat back frame hooks from the footmans loops bolted
to the rear cab back. (Fig. 18)
(4) Remove the seats from the vehicle.
INSTALLATION
(1) Install the seats into the vehicle and engage
the seat back frame hooks with the footmans loops in
the cab back panel.
(2) Install the rear seat bolts and tighten to 40
N´m (30 ft. lbs.).
(3) Install the load floor. (Refer to 23 - BODY/IN-
TERIOR/LOAD FLOOR - INSTALLATION)
SEAT BACK - REAR
REMOVAL
(1) Remove the rear seat. (Refer to 23 - BODY/
SEATS/SEAT - REAR - REMOVAL)
(2) Remove the seat back bolts and remove the
seat back. (Fig. 19)
INSTALLATION
(1) Install the seat back and install the bolts.
(2) Tighten the bolts to 25 N´m (18 ft. lbs.).
Fig. 17 SEAT ATTACHMENT
1 - OUTER BOLTS (2)
2 - REAR SEAT ASSEMBLY
3 - INNER BOLTS (4)
4 - REAR SEAT BACK
5 - OUTER BOLTS (2)
DRSEATS 23 - 83

ber above the heating, ventilation and air condition-
ing (HVAC) housing. On models equipped with air
conditioning, the air passes through the evaporator
coil. Air flow can be directed either through or
around the heater core. This is done by adjusting the
blend door with the temperature control knob on the
A/C-heater control located the instrument panel. The
air flow can then be directed from the panel, floor
and defrost outlets in various combinations using the
mode control knob located on the A/C-heater control.
Air flow velocity can be adjusted with the blower
speed selector located on the A/C-heater control.
NOTE: It is important to keep the air intake opening
clear of debris. Leaf particles and other debris that
is small enough to pass through the cowl opening
screen can accumulate within the HVAC housing.
The closed, warm, damp and dark environment cre-
ated within the housing is ideal for the growth of
certain molds, mildews and other fungi. Any accu-mulation of decaying plant matter provides an addi-
tional food source for fungal spores, which enter
the housing with the fresh intake-air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during heater-A/C
operation if the air intake opening is not kept clear
of debris.
The heater and air conditioning systems are blend-
air type systems. In a blend-air system, a blend door
controls the amount of unconditioned air (or cooled
air from the evaporator on models with air condition-
ing) that is allowed to flow through, or around, the
heater core. A temperature control knob determines
the discharge air temperature by actuating an elec-
tric motor, which operates the blend door. This allows
an almost immediate control of the output air tem-
perature of the system.
On all models, the outside air intake can be shut
off by selecting the Recirculation Mode with the
mode control knob. This will operate a electric actu-
ated recirculation air door that closes off the outside
fresh air intake and recirculates the air that is
already inside the vehicle.
The air conditioning compressor can be engaged in
any mode by pressing the snowflake, A/C on/off but-
ton. It can also be engaged by placing the mode con-
trol in the mix to defrost positions. This will remove
heat and humidity from the air before it is directed
through or around the heater core. The mode control
knob on the A/C-heater control is used to also direct
the conditioned air to the selected system outlets.
The mode control switch uses an electric motor to
control the mode doors.
The defroster outlet receives airflow from the
HVAC housing through the molded plastic defroster
duct, which connects to the HVAC housing defroster
outlet. The airflow from the defroster outlets is
directed by fixed vanes in the defroster outlet grilles
and cannot be adjusted. The defroster outlet grilles
are integral to the instrument panel top cover.
The side window demister outlets receive airflow
from the HVAC housing through the molded plastic
defroster duct and two molded plastic demister ducts.
The airflow from the side window demister outlets is
directed by fixed vanes in the demister outlet grilles
and cannot be adjusted. The side window demister
outlet grilles are integral to the instrument panel.
The demisters direct air from the HVAC housing
through the outlets located on the top corners of the
instrument panel. The demisters operate when the
mode control knob is positioned in the floor-defrost
and defrost-only settings. Some air may be noticeable
from the demister outlets when the mode control is
in the bi-level to floor positions.
Fig. 1 HVAC Housing - Dual Zone Shown, Single
Zone Typical
1 - NUT
2 - PASSENGER BLEND DOOR ACTUATOR
3 - NUT
4 - INLET BAFFLE
5 - RECIRCULATION DOOR ACTUATOR
6 - RECIRCULATION DOOR
7 - DRIVER SIDE BLEND DOOR ACTUATOR
8 - HVAC HOUSING
9 - BOLT
10 - DEFROSTER DOOR ACTUATOR
11 - MODE DOOR ACTUATOR
24 - 2 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)

The panel outlets receive airflow from the HVAC
housing through a molded plastic main panel duct,
center panel duct and two end panel ducts. The two
end panel ducts direct airflow to the left and right
instrument panel outlets, while the center panel duct
directs airflow to the two center panel outlets. Each
of these outlets can be individually adjusted to direct
the flow of air.
The floor outlets receive airflow from the HVAC
housing through the floor distribution duct. The front
floor outlets are integral to the molded plastic floor
distribution duct, which is secured to the bottom of
the housing. The floor outlets cannot be adjusted.
The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a fixed
orifice tube in the liquid line near the condenser out-
let tube to meter refrigerant flow to the evaporator
coil. To maintain minimum evaporator temperature
and prevent evaporator freezing, a evaporator tem-
perature sensor is used. The JTEC control module is
programmed to respond to the evaporator tempera-
ture sensor input by cycling the air conditioning com-
pressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to remove
heat and humidity from the air entering the passen-
ger compartment. The evaporator, located in the
HVAC housing, 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 Recirculation
mode, only air from the passenger compartment
passes through the evaporator. As the passenger com-
partment air dehumidifies, A/C performance levels
rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the air condition-
ing system. When humidity is high, the evaporator
has to perform a double duty. It must lower the air
temperature, and it must lower the temperature ofthe moisture in the air that condenses on the evapo-
rator fins. Condensing the moisture in the air trans-
fers heat energy into the evaporator fins and tubing.
This reduces the amount of heat the evaporator can
absorb from the air. High humidity greatly reduces
the ability of the evaporator to lower the temperature
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
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
PERFORMANCE TEST PROCEDURE
Review Safety Warnings and Cautions before per-
forming this procedure (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION). Air temperature in test
room and on vehicle must be 21É C (70É 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 a manifold gauge set
or A/C recycling/charging station.
(2) Set the A/C-heater mode control in the Recircu-
lation Mode position, the temperature control knob in
the full cool position, and the blower motor switch to
the highest speed position.
(3) Start the engine and hold at 1,000 rpm with
the A/C compressor clutch engaged.
(4) The engine should be warmed up to operating
temperature with the doors closed and windows
open.
(5) Insert a thermometer in the driver side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.
(7) With the compressor clutch engaged, record the
discharge air temperature and the compressor dis-
charge pressure.
(8) If the discharge air temperature fails to meet
the specifications in the A/C Performance Tempera-
ture chart, refer to the Pressure Diagnosis chart.
DRHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)

PERFORMANCE TEMPERATURE AND PRESSURE
Ambient Air
Temperature21É C
(70É F)27É C
(80É F)32É C
(90É F)38É C
(100É F)43É C
(110É F)
Air Temperature at
Center Panel Outlet7É C
(45É F)7É C
(45É F)13É C
(55É F)13É C
(55É F)18É C
(64É F)
Compressor Inlet
Pressure at Service
Port (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 Pressure at
Service Port (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)
(9) Compare the compressor discharge pressure to
the Performance Temperature and Pressure chart. Ifthe compressor discharge pressure is high, see the
Pressure Diagnosis chart.
PRESSURE DIAGNOSIS
Condition Possible Causes Correction
Constant compressor
engagement and warm air
from passenger vents.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
Equal pressures, but the
compressor clutch does not
engage.1. No refrigerant in the
refrigerant system.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
2. Faulty fuse. 2. Check the fuses in the Power Distribution
Center and the junction block. Repair the shorted
circuit or component and replace the fuses, if
required.
3. Faulty A/C compressor
clutch coil.3. See A/C Compressor Clutch Coil in this group.
Test the compressor clutch coil and replace, if
required.
4. Faulty A/C compressor
clutch relay.4. See A/C Compressor Clutch Relay in this
group. Test the compressor clutch relay and relay
circuits. Repair the circuits or replace the relay, if
required.
5. Improperly installed or
faulty Evaporator
Temperature Sensor.5. See Evaporator Temperature Sensor in this
group. Reinstall or replace the sensor as
required.
6. Faulty A/C pressure
transducer.6. See A/C pressure transducer in this group.
Test the switch and replace, if required.
7. Faulty Powertrain Control
Module (PCM).7. (Refer to Appropriate Diagnostic Information).
Test the PCM and replace, if required.
24 - 4 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)

DISASSEMBLY
(1) Remove the HVAC housing from the vehicle
and place it on the workbench (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL).
(2) Disconnect the electrical connectors from the
blower motor, blower motor resistor block, evaporator
temperature sensor and each actuator (Fig. 10).
(3) Remove the HVAC wiring harness from the
HVAC housing.
(4) If necessary, remove the blower motor from
the HVAC housing (Refer to 24 - HEATING & AIR
CONDITIONING/DISTRIBUTION/BLOWER
MOTOR - REMOVAL).
(5) If necessary, remove the blower motor resistor
block from the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - REMOVAL).
(6) Carefully remove the foam seals from the
heater core and evaporator coil tube mounting flange
of the HVAC housing. If the either seal is deformed
or damaged, it must be replaced.
(7) Remove the screws that secure the heater core
in the HVAC housing and carefully remove the
heater core from the housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/HEATER
CORE - REMOVAL).(8) Use a screwdriver to pry off the four snap clips
that help secure the upper and lower HVAC housing
halves together.
(9) Remove the screws that secure the upper and
lower HVAC housing halves to each other and those
that secure the recirculation housing to the upper
HVAC housing.
(10) Carefully separate the recirculation housing
and the upper HVAC housing from the lower hous-
ing.
ASSEMBLY
(1) Position the upper HVAC housing to the lower
housing. During assembly, be certain of the following:
(a) That each of the door pivot shaft ends are
properly engaged in there pivot holes.
(b) That the evaporator drain opening is clean
and the drain foam seal is properly installed.
(2) Install the screws and snap clips that secure
the upper and lower HVAC housing halves to each
other and those that secure the recirculation housing
to the upper HVAC housing. Tighten the screws to
2.2 N´m (20 in. lbs.).
(3) Install the foam seals on the heater core and
evaporator coil tubes.
(4) If removed, install the blower motor resistor
block (Refer to 24 - HEATING & AIR CONDITION-
Fig. 10 HVAC Housing - Disassembled
1 - RECIRCULATION HOUSING
2 - RECIRC DOOR ACTUATOR
3 - DRIVER SIDE BLEND DOOR ACTUATOR
4 - FLOOR DISTRIBUTION DUCT
5 - DEFROST DOOR ACTUATOR
6 - PANEL DOOR ACTUATOR
7 - UPPER HVAC HOUSING
8 - PASSENGER SIDE BLEND DOOR ACTUATOR9 - HEATER CORE
10 - LOWER HVAC HOUSING
11 - HVAC WIRE HARNESS
12 - DRAIN FOAM SEAL
13 - BLOWER MOTOR
14 - EVAPORATOR FOAM SEAL
15 - EVAPORATOR
16 - HEATER CORE FOAM SEAL
DRDISTRIBUTION 24 - 35
HVAC HOUSING (Continued)

that secure the mode door adapter to the front the
HVAC housing.
(6) Install the two screws that secure the mode
door adapter to the top of the HVAC housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(7) Install the mode door actuator and sleeve to
the upper half of the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/
MODE DOOR ACTUATOR - INSTALLATION).
(8) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
RECIRCULATION DOOR
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove the HVAC housing from the vehicle
and place it on the workbench (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL).
(2) Remove the recirculation door actuator from
the recirculation housing (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/RECIRCULA-
TION DOOR ACTUATOR - REMOVAL).
(3) Remove the two screws and disengage the two
plastic retaining tabs that secure the recirculation
housing to the HVAC housing (Fig. 14).
(4) Remove the recirculation housing from the
HVAC housing.
(5) Gently slide the recirculation door toward the
outside of the recirculation housing. Tilt and lift the
door out of the housing.
(6) Inspect the recirculation door, seals and the
HVAC recirculation housing for damage or binding
and repair or replace components as required.
Fig. 13 HVAC Mode Door
1 - MODE DOOR ADAPTER
2 - SPRING RETAINER
3 - SCREW (2)
4 - MODE DOOR ACTUATOR
5 - MODE DOOR
DRDISTRIBUTION 24 - 39
MODE DOOR (Continued)

After the system has been tested for leaks and
evacuated, a refrigerant (R-134a) charge can be
injected into the system.
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) If using a separate vacuum pump close all
valves before disconnecting pump. Connect manifold
gauge set to the A/C service ports.
NOTE: Always refer to the underhood HVAC Speci-
fication label for the refrigerant fill level of the vehi-
cle being serviced.
(2) Measure refrigerant (refer to capacities). Refer
to the instructions provided with the equipment
being used.
(3) Verify engine is shut off. Open the suction and
discharge valves. Open the charge valve to allow the
refrigerant to flow into the system. When the trans-
fer of refrigerant has stopped, close the suction and
discharge valve.
(4) If all of the charge did not transfer from the
dispensing device, put vehicle controls into the fol-
lowing mode:
²Automatic transmission in park or manual
transmission in neutral
²Engine at idle
²A/C mode control set to outside air
²A/C mode control set to panel mode
²A/C temperature control set to full cool
²Blower motor control set on highest speed
²Vehicle windows closed
If the A/C compressor does not engage, test the
compressor clutch control circuit and correct any fail-
ure (Refer to 8 - ELECTRICAL/WIRING DIAGRAM
INFORMATION - DIAGNOSIS AND TESTING).
(5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system perfor-
mance.
(7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
REFRIGERANT CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood HVAC
specfication tag.
A/C COMPRESSOR
DESCRIPTION
DESCRIPTION - A/C COMPRESSOR
The A/C system on models equipped with the 5.9L
engine use a Sanden SD-7 reciprocating swash plate-
type compressor. This compressor has a fixed dis-
placement of 165 cubic centimeter (10.068 cubic
inches) and has both the suction and discharge ports
located on the cylinder head.
The A/C system on models equipped with the 3.7L,
4.7L and 5.7L engines use a Denso 10S17 reciprocat-
ing swash plate-type compressor. This compressor
has a fixed displacement of 170 cubic centimeter and
has both the suction and discharge ports located on
the cylinder head.
A label identifying the use of R-134a refrigerant is
located on both A/C compressors.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the com-
pressor cylinder head, which is on the rear of the
compressor. This mechanical valve is designed to
vent refrigerant from the system to protect against
damage to the compressor and other system compo-
nents, caused by condenser air flow restriction or an
overcharge of refrigerant.
OPERATION
OPERATION - A/C COMPRESSOR
The A/C compressor is driven by the engine
through an electric clutch, drive pulley and belt
arrangement. The compressor is lubricated by refrig-
erant oil that is circulated throughout the refrigerant
system with the refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley and clutch
coil are available for service.
OPERATION - HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes
24 - 48 PLUMBINGDR
PLUMBING (Continued)

(11) Remove the tape or plugs from the discharge
line fitting and condenser inlet port.
(12) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting. Use only the specified O-ring as it is made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the A/C
compressor in the vehicle.
(13) Connect the discharge line to the condenser
inlet port.
(14) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 20 N´m (180 in. lbs.).
(15) Connect the wire harness connector to the A/C
pressure transducer.
(16) Reconnect the battery negative cable.
(17) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(18) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
INSTALLATION - 3.7L/4.7L AND 5.7L HEMI
ENGINE
(1) If removed, install the A/C pressure transducer
onto the discharge line using a new O-ring seal.
Tighten the transducer securely.
(2) Position the discharge line into the engine com-
partment.
(3) Remove the tape or plugs from the discharge
line fitting and the compressor outlet port.
(4) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting. Use only the specified O-ring as it is made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the A/C
compressor in the vehicle.
(5) Connect the discharge line to the compressor.
(6) Install and tighten the nut that secures the
discharge line to the compressor. Tighten the nut to
28 N´m (20 ft. lbs.).
(7) Remove the tape or plugs from the discharge
line fitting and condenser inlet port.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting. Use only the specified O-ring as it is made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the A/C
compressor in the vehicle.(9) Connect the discharge line to the condenser
inlet port.
(10) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 20 N´m (180 in. lbs.).
(11) Connect the wire harness connector to the A/C
pressure transducer.
(12) Reconnect the battery negative cable.
(13) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(14) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
A/C EVAPORATOR
DESCRIPTION
The A/C evaporator is located in the HVAC hous-
ing, behind the instrument panel. The evaporator is
positioned in the HVAC housing so that all air that
enters the housing must pass over the fins of the
evaporator coils before it is distributed through the
system ducts and outlets. However, air passing over
the evaporator fins will only be conditioned when the
compressor is engaged and circulating refrigerant
through the evaporator tubes.
OPERATION
Refrigerant enters the A/C evaporator from the
fixed orifice tube as a low-temperature, low-pressure
mixture of liquid and gas. As air flows over the fins
of the A/C evaporator, the humidity in the air con-
denses on the fins, and the heat from the air is
absorbed by the refrigerant. Heat absorption causes
the refrigerant to boil and vaporize. The refrigerant
becomes a low-pressure gas before it leaves the A/C
evaporator.
The A/C evaporator cannot be repaired and, if
faulty or damaged, it must be replaced.
DRPLUMBING 24 - 59
A/C DISCHARGE LINE (Continued)

DIAGNOSIS AND TESTING - A/C ORIFICE TUBE
WARNING: THE LIQUID LINE BETWEEN THE CON-
DENSER OUTLET AND THE A/C ORIFICE TUBE
CAN BECOME HOT ENOUGH TO BURN THE SKIN.
USE EXTREME CAUTION WHEN PERFORMING THE
FOLLOWING TEST.
NOTE: The A/C orifice tube can be checked for
proper operation using the following procedure.
However, the A/C orifice tube is only serviced as a
part of the liquid line. If the results of this test indi-
cate that the A/C orifice tube is obstructed or miss-
ing, the liquid line must be replaced.
(1) Confirm that the refrigerant system is properly
charged. (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING - A/C PER-
FORMANCE)
(2) Start the engine. Turn on the air conditioning
system and confirm that the compressor clutch is
engaged.
(3) Allow the air conditioning system to operate for
five minutes.
(4) Lightly and cautiously touch the liquid line
near the condenser outlet at the front of the engine
compartment. The liquid line should be hot to the
touch.
(5) Touch the liquid line near the evaporator inlet
at the rear of the engine compartment. The liquid
line should be cold to the touch.
(6) If there is a distinct temperature differential
between the two ends of the liquid line, the A/C ori-
fice tube is in good condition. If there is little or no
detectable temperature differential between the two
ends of the liquid line, the A/C orifice tube is
obstructed or missing and the liquid line must be
replaced.
ACCUMULATOR
DESCRIPTION
The accumulator (Fig. 21) is mounted in the engine
compartment between the evaporator outlet and the
compressor suction port. An integral mounting
bracket is used to secure the accumulator to the dash
panel.
The accumulator cannot be repaired and, if faulty
or damaged, it must be replaced. The rubber O-rings
are available for service replacement.
OPERATION
Refrigerant enters the accumulator canister as a
low pressure vapor through the inlet tube. Any liq-
uid, oil-laden refrigerant falls to the bottom of thecanister, which acts as a separator. A desiccant bag is
mounted inside the accumulator canister to absorb
any moisture which may have entered and become
trapped within the refrigerant system.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
Fig. 21 Accumulator - Typical
1 - A/C LOW PRESSURE SWITCH (IF EQUIPPED)
2 - PRESSURE SWITCH FITTING
3 - OUTLET TO COMPRESSOR
4 - ANTI-SIPHON HOLE
5 - DESICCANT BAG
6 - OIL RETURN ORIFICE FILTER
7 - VAPOR RETURN TUBE
8 - ACCUMULATOR DOME
9 - O-RING SEAL
10 - INLET FROM EVAPORATOR
DRPLUMBING 24 - 61
A/C ORIFICE TUBE (Continued)