Page 5121 of 5267

MOTOR-BLOWER
DESCRIPTION
The blower motor (1) is used to control the velocity of
air moving through the HVAC housing by spinning the
blower wheel (3) within the HVAC air inlet housing at
the selected speed.
The blower motor is a 12-volt, direct current (DC)
motormountedwithinaplastichousingwithaninte-
gral wire harness connector (2) and squirrel cage-type
blower wheel (3) that is secured to the blower motor
shaft (4). The blower wheel is positioned within the air
inlet housing on the passenger side end of the HVAC
housing.
OPERATION
The blower motor is used to control the velocity of air moving through the HVAC housing by spinning the blower
wheel within the HVAC air inlet housing at the selected speed.
The blower motor will operate whenever the ignition switch is in the Run position and the blower motor control is in
any position except Off. The blower motor receives battery current through the totally integrated power module
(TIPM) whenever the ignition switch is in the Run position.
Blower motor speed is controlled by regulating the ground path through or around the blower motor resistor and
through the blower motor control located within the A/C-heater control.
The blower motor can be accessed for service from underneath the instrument panel.
NOTE: The blower motor is supplied with a 12V feed from the TIPM, through theresistor block, whenever
the ignition switch is in the RUN position. Due to an open circuit conditionwithin the blower motor control
switch the TIPM is UNABLE to detect an OPEN circuit for the blower motor.
The blower motor control system is diagnosed using a scan tool (Refer to 24 -HVAC Electrical Diagnostics for more
information).
The blower motor and blower wheel are factory balanced and cannot be adjusted or repaired. If faulty or damaged,
the blower motor and wheel must be replaced as an assembly.
DIAGNOSIS AND TESTING
BLOWER MOTOR
WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering
wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the
negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before
performing further diagnosis or service. Failure to take the proper precautions could result in accidental
airbag deployment and possible personal injury or death.
Page 5122 of 5267

NOTE: The blower motor is supplied with a 12V feed from the TIPM, through theresistor block, whenever
the ignition switch is in the RUN position. Due to an open circuit conditionwithin the blower motor control
switch the TIPM is UNABLE to detect an OPEN circuit for the blower motor.
To determine if an open condition exists within the blower motor circuit wiring, it is necessary to disconnect the
negative battery cable and check for continuity within the blower motor circuits using an ohmmeter. For circuit
descriptions and diagrams, refer to Air Conditioning/Heater in Group 8W -Wiring Diagrams.
OPERATION
Possible causes of the blower motor not operating include:
Faulty blower motor
Faulty blower motor circuit wiring or wire harness connectors
Faulty blower motor control
Possible causes of the blower motor not operating in one or more speeds include:
Faulty blower motor resistor
Faulty blower motor circuit wiring or wire harness connectors
Faulty blower motor control
VIBRATION
Possible causes of blower motor vibration include:
Improper blower motor mounting
Improper blower wheel mounting
Deformed blower wheel
Out of balance blower wheel due to foreign material in the wheel
Faulty blower motor
NOISE
To determine if the blower motor is the source of the noise, simply switch the blower motor from Off to On. To verify
that the blower motor is the source of the noise, unplug the blower motor wire harness connector and operate the
heating-A/C system. If the noise goes away, possible causes include:
Foreign material in the HVAC air inlet housing
Improper blower motor mounting
Improper blower wheel mounting
Faulty blower motor
Page 5123 of 5267

REMOVAL
NOTE: The blower motor is located on the passen-
ger side of the vehicle under the instrument panel.
The blower motor can be removed from the vehi-
cle without having to remove the HVAC housing.
1. Disconnect and isolate the negative battery cable.
2. Remove the passenger side cowl trim panel (Refer
to 23 - BODY/INTERIOR/COWL TRIM PANEL -
REMOVAL).
3. Disconnect the HVAC wire harness lead (1) from
the blower motor (2).
4. Remove the HVAC wire harness lead from the two
wire harness retainers (3).
5. Remove the three screws (4) that secure the
blower motor to the bottom of the HVAC housing
(5).
6. Remove the blower motor from the HVAC housing.
INSTALLATION
1. Position the blower motor (2) into the bottom of the
HVAC housing (5).
2. Install the three screws (4) that secure the blower
motor to the HVAC housing. Tighten the screws to
2.2 Nꞏm (20 in. lbs.).
3. Connect the HVAC wire harness lead (1) to the
blower motor and install the wire harness lead into
the two wire harness retainers (3).
4. Install the passenger side cowl trim panel (Refer to
23 - BODY/INTERIOR/COWL TRIM PANEL -
INSTALLATION).
5. Reconnect the negative battery cable.
Page 5124 of 5267

OUTLETS-AIR
DESCRIPTION
There are four defroster air outlets (1) in the defroster
grille (2) located on the top of the instrument panel
(3). The airflow from the defroster outlets is directed
by fixed vanes in the defroster grille and cannot be
adjusted. The defroster air outlets are not serviceable
from the defroster grille (Refer to 23 - BODY/INSTRU-
MENT PANEL/DEFROSTER GRILLE - REMOVAL).
There are two side window demister air outlets (4).
One located on each end of the instrument panel near
the A-pillar area. The airflow from the side window
demister air outlets is directed by fixed vanes in the
outlets and cannot be adjusted. The driver side win-
dow demister air outlet is serviced with the instrument
cluster bezel and the passenger side demister outlet is
serviced with the instrument panel cover (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT CLUS-
TER BEZEL - REMOVAL and 23 - BODY/INSTRU-
MENT PANEL/COVER-INSTRUMENT PANEL -
REMOVAL).
There are four instrument panel air outlets (5). One air outlet is located near the end of the instrument panel facing
the rear of the vehicle and two outlets are located on the instrument panel center bezel. Each of the instrument
panel air outlets contain a grille with movable vanes that are used to direct or shut off the flow of the conditioned air
leaving the instrument panel outlets. The driver side instrument panel air outlet is serviced with the instrument clus-
ter bezel, the passenger side instrument panel air outlet is serviced withthe instrument panel cover and the two
center air outlets are serviced with the center bezel (Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
CLUSTER BEZEL - REMOVAL), (23 - BODY/INSTRUMENT PANEL/COVER-INSTRUMENTPA N E L - R E M O VA L )
and )23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL CENTER BEZEL - REMOVAL).
On Mega Cab models there are two outlets located at
the rear of the center front seat. Each of the rear air
outlets contain a grille withmovable vanes that are
used to direct or shut off the flow of the conditioned air
leaving the outlets. The rear air outlets are not ser-
viceable.
Page 5125 of 5267

page page
PLUMBING
DESCRIPTION ............................... 286
OPERATION ................................. 286
WARNING ................................... 286
CAUTION ................................... 287
DIAGNOSIS AND TESTING
REFRIGERANT SYSTEM LEAKS ............ 288
STANDARD PROCEDURE
REFRIGERANT SYSTEM SERVICE
EQUIPMENT............................... 289
REFRIGERANT SYSTEM RECOVERY ....... 290
REFRIGERANT SYSTEM EVACUATE ........ 290
REFRIGERANT SYSTEM CHARGE .......... 291
ACCUMULATOR-A/C
DESCRIPTION ............................... 292
OPERATION ................................. 292
REMOVAL ................................... 292
INSTALLATION .............................. 293
COMPRESSOR-A/C
DESCRIPTION
A/C COMPRESSOR........................ 295
HIGH PRESSURE RELIEF VALVE ........... 295
OPERATION
A/C COMPRESSOR........................ 295
HIGH PRESSURE RELIEF VALVE ........... 295
DIAGNOSIS AND TESTING
A/C COMPRESSOR........................ 296
REMOVAL
3.7L/4.7L ENGINES ........................ 296
5.7L ENGINE .............................. 297
5.9L DIESEL ENGINE ...................... 298
8.3L ENGINE .............................. 299
INSTALLATION
3.7L/4.7L ENGINES ........................ 300
5.7L ENGINE .............................. 301
5.9L DIESEL ENGINE ...................... 302
8.3L ENGINE .............................. 303
CONDENSER-A/C
DESCRIPTION ............................... 305
OPERATION ................................. 305
REMOVAL
3.7L/4.7L/5.7L ENGINES .................... 305
5.9L DIESEL ENGINE ...................... 305
8.3L ENGINE .............................. 306
INSTALLATION
3.7L/4.7L/5.7L ENGINES .................... 307
5.9L DIESEL ENGINE ...................... 307
8.3L ENGINE .............................. 308
CORE-HEATER
DESCRIPTION ............................... 310
OPERATION ................................. 310REMOVAL ................................... 310
INSTALLATION .............................. 311
CORE-VALVE-SERVICE PORT
DESCRIPTION ............................... 312
REMOVAL ................................... 312
INSTALLATION .............................. 313
COUPLER-REFRIGERANT LINE
DESCRIPTION ............................... 314
OPERATION ................................. 314
REMOVAL ................................... 314
INSTALLATION .............................. 315
EVAPORATOR-A/C
DESCRIPTION ............................... 317
OPERATION ................................. 317
REMOVAL ................................... 317
INSTALLATION .............................. 318
FAN-A/C CONDENSER
DESCRIPTION ............................... 319
OPERATION ................................. 319
REMOVAL ................................... 319
INSTALLATION .............................. 320
LINE-A/C DISCHARGE
DESCRIPTION ............................... 321
REMOVAL
3.7L/4.7L ENGINES ........................ 321
5.7L ENGINE .............................. 322
5.9L DIESEL ENGINE...................... 322
8.3L ENGINE .............................. 323
INSTALLATION
3.7L/4.7L ENGINES ........................ 325
5.7L ENGINE .............................. 326
5.9L DIESEL ENGINE...................... 326
8.3L ENGINE .............................. 328
LINE-A/C LIQUID
DESCRIPTION ............................... 330
REMOVAL
3.7L/4.7L/5.7L/5.9L ENGINES ............... 330
8.3L ENGINE .............................. 331
INSTALLATION
3.7L/4.7L/5.7L/5.9L ENGINES ............... 333
8.3L ENGINE .............................. 334
LINE-A/C SUCTION
DESCRIPTION ............................... 337
REMOVAL
3.7L/4.7L ENGINES ........................ 337
5.7L ENGINE .............................. 338
5.9L DIESEL ENGINE...................... 339
8.3L ENGINE .............................. 340
INSTALLATION
3.7L/4.7L ENGINES ........................ 342
5.7L ENGINE .............................. 343
Page 5126 of 5267
5.9L DIESEL ENGINE ...................... 343
8.3L ENGINE .............................. 345
OIL-A/C REFRIGERANT
DESCRIPTION ............................... 347
OPERATION ................................. 347
STANDARD PROCEDURE
REFRIGERANT OIL LEVEL ................. 347
REFRIGERANT-A/C
DESCRIPTION ............................... 349OPERATION ................................. 349
TUBE-A/C ORIFICE
DESCRIPTION ............................... 350
OPERATION ................................. 350
DIAGNOSIS AND TESTING
A/C ORIFICE TUBE ........................ 350
Page 5127 of 5267

PLUMBING
DESCRIPTION
The A/C refrigerant lines and hoses are used to carry the refrigerant between the various A/C system components.
The refrigerant lines and hoses for the R-134a system on this vehicle consist of a barrier-hose design with a nylon
tube sandwiched between rubber layers. The nylon tube helps to contain theR-134a refrigerant, which has a
smaller molecular structure than R-12 refrigerant. The ends of the refrigerant lines are made from lightweight alu-
minum or steel, and commonly use braze-less fittings.
Any kinks or sharp bends in the refrigerant lines and hoses will reduce the capacity of the entire A/C system and
can reduce the flow of refrigerant in the system. The radius of all bends in the flexible hose refrigerant lines should
be at least ten times the diameter of the hose and the refrigerant lines should be routed so they are at least 80
millimeters (3 inches) away from the exhaust manifold(s) and exhaust pipe(s).
OPERATION
High pressures are produced in the refrigerant system when the A/C compressor is operating. Extreme care must
be exercised to make sure that each of the refrigerant system connections is pressure-tight and leak free. It is a
good practice to inspect all flexible hose refrigerant lines at least oncea year to make sure they are in good con-
dition and properly routed.
The refrigerant lines and hoses are coupled to other A/C system componentswith block-type fittings. An O-ring seal,
or a flat steel gasket with an integral O-ring (dual plane seal), is used to mate the refrigerant line fittings with A/C
system components to ensure the integrity of the refrigerant system.
The refrigerant lines and hoses cannot be repaired and, if faulty or damaged, they must be replaced.
WARNING
WARNING: The A/C system contains refrigerant under high pressure. Repairs should only be performed by
qualified service personnel. Severe personal injury or death may result from improper service procedures.
WARNING: Avoid breathing the refrigerant and refrigerant oil vapor or mist. Exposure may irritate the eyes,
nose, and/or throat. Wear eye protection when servicing the A/C refrigerant system. Serious eye injury can
result from direct contact with the refrigerant. If eye contact occurs, seek medical attention immediately.
WARNING: Do not expose the refrigerant to open flame. Poisonous gas is createdwhenrefrigerantis
burned. An electronic leak detector is recommended. Severe personal injury or death may result from
improper service procedures.
WARNING: If accidental system discharge occurs, ventilate the work area before resuming service. Large
amounts of refrigerant released in a closed work area will displace the oxygen and cause suffocation and
death.
WARNING: The evaporation rate of R-134a refrigerant at average temperature and altitude is extremely high.
As a result, anything that comes in contact with the refrigerant will freeze. Always protect the skin or del-
icate objects from direct contact with the refrigerant.
WARNING: The R-134a service equipment or the vehicle refrigerant system should not be pressure tested or
leak tested with compressed air. Some mixtures of air and R-134a have been shown to be combustible at
elevated pressures. These mixtures are potentially dangerous, and may result in fire or explosion causing
property damage, personal injury or death.
Page 5128 of 5267

WARNING: The engine cooling system is designed to develop internal pressures up to 145 kilopascals (21
pounds per square inch). Do not remove or loosen the coolant pressure cap, cylinder block drain plugs,
radiator drain, radiator hoses, heater hoses, or hose clamps while the engine cooling system is hot and
under pressure. Allow the vehicle to cool for a minimum of 15 minutes beforeopening the cooling system
for service. Failure to observe this warning can result in serious burns from the heated engine coolant.
CAUTION
CAUTION: Never add R-12 to a refrigerant system designed to use R-134a. Do not use R-12 equipment or
parts on an R-134a A/C system. These refrigerants are not compatible and damage to the A/C system will
result.
CAUTION: Never use R-12 refrigerant oil in a A/C system designed to use R-134a refrigerant oil. These
refrigerant oils are not compatible and damage to the A/C system will result.
CAUTION: The use of A/C system sealers may result in damage to A/C refrigerant recovery/evacuation/re-
charging equipment and/or A/C system. Many federal, state/provincial and local regulations prohibit the
recharge of A/C systems with known leaks. DaimlerChrysler recommends thedetection of A/C system leaks
through the use of approved leak detectors and fluorescent leak detectiondyes. Vehicles found with A/C
system sealers should be treated as contaminated and replacement of the entire A/C refrigerant system is
recommended. A/C systems found to be contaminated with A/C system sealers, A/C stop-leak products or
seal conditioners voids the warranty for the A/C system.
CAUTION: Recover the refrigerant before opening any fitting or connection. Open the fittings with caution,
even after the system has been discharged. Never open or loosen a connection before recovering the refrig-
erant.
CAUTION: If equipped, do not remove the secondary retention clip from any spring-lock coupler connection
while the refrigerant system is under pressure. Recover the refrigerant before removing the secondary
retention clip. Open the fittings with caution, even after the system has been discharged. Never open or
loosen a connection before recovering the refrigerant.
CAUTION: The internal parts of the A/C system will remain stable as long as moisture-free refrigerant and
refrigerant oil is used. Abnormal amounts of dirt, moisture or air can upset the chemical stability. This may
cause operational troubles or even serious damage if present in more than very small quantities. Before
disconnecting a component, clean the outside of the fittings thoroughly to prevent contamination from
entering the refrigerant system. Keep service tools and the work area clean. Do not open the refrigerant
system or uncap a replacement component until you are ready to service the system. Immediately after
disconnecting a component from the refrigerant system, seal the open fittings with a cap or plug. This will
prevent contamination from entering the A/C system.
CAUTION: Refrigerant oil will absorb moisture from the atmosphere if leftuncapped. Do not open a con-
tainer of refrigerant oil until you are ready to use it. Replace the cap on the oil container immediately after
using. Store refrigerant oil only in a clean, airtight, and moisture-freecontainer.
CAUTION: Do not overcharge the refrigerant system. Overcharging will cause excessive compressor head
pressure and can cause compressor noise and A/C system failure.