2002 JEEP GRAND CHEROKEE radiator

WELD LOCATIONS
SPECIFICATIONS
WELD LOCATIONS
INDEX
DESCRIPTION FIGURE
RADIATOR SUPPORT BRACKETS 49
FRONT SUSPENSION SUPPORT REINFORCEMENT 50
FRONT LOWER CROSSMEMBER TO COWL SIDE PANEL 51
FRONT SILL TO LOWER CROSSMEMBER 52
FRONT FENDER MOUNTING BRACKET AND REINFORCEMENT 53
FRONT SUSPENSION SUPPORT TO SILLS AND COWL SIDE PANEL 54
LEFT INSTRUMENT PANEL BRACKET TO COWL SIDE PANEL 55
COWL SIDE UPPER REINFORCEMENT TO COWL SIDE AND FRONT SUSPENSION
SUPPORT56
COWL SIDE PANEL TO DASH PANEL AND INNER BODYSIDE PANEL AND SILL 57
PLENUM ASSEMBLY TO COWL SIDE PANEL 58
FRONT LOWER CROSSMEMBER 59
FRONT SUSPENSION SUPPORT TO DASH 60
WIPER MOUNTING BRACKETS TO PLENUM ASSEMBLY 61
COWL TOP AND PLENUM ASSEMBLY 62
LOWER PLENUM REINFORCEMENT TO LOWER PLENUM PANEL 63
DASH PANEL TO LOWER PLENUM PANEL 64
PLENUM ASSEMBLY TO COWL 65
COWL PANEL TO BODYSIDE SILL 66
COWL PANEL TO FRONT FLOOR PAN 67
FRONT SILLS TO DASH AND FRONT FLOOR PAN 68
COWL SIDE PANEL DASH INNER BODYSIDE AND OUTER BODYSIDE PANELS 69
UPPER FRONT INNER PILLAR TO ROOF AND COWL 70
DOOR OPENINGS 71
B-PILLAR REINFORCEMENT TO INNER BODYSIDE APERTURE 72
REAR QUARTER WINDOW TO BODYSIDE APERTURE INNER AND OUTER 73
LOWER REAR QUARTER TO BODYSIDE APERTURE INNER AND OUTER 74
INNER TRACK BAR, LOWER CONTROL ARM AND TRANSMISSION CROSSMEMBER
BRACKETS TO FRONT SILLS75
TRANSMISSION CROSSMEMBER BRACKET AND REINFORCEMENT TO FRONT
SILLS76
UPPER SILLS AND UPPER CONTROL ARM REINFORCEMENT AND BRACKETS TO
FRONT SILLS77
REINFORCEMENT TO FRONT OUTER SILLS 78
FRONT INNER SILL TO FRONT OUTER SILL 79
OUTER TRACK BAR BRACKET TO FRONT OUTER SILL 80
WJBODY STRUCTURE 23 - 153

Fig. 49 RADIATOR SUPPORT BRACKETS
Fig. 50 FRONT SUSPENSION SUPPORT REINFORCEMENT
WJBODY STRUCTURE 23 - 155
WELD LOCATIONS (Continued)

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS.......................1
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT........................1
OPERATION
OPERATION - HEATER AND AIR
CONDITIONER........................2
OPERATION - REFRIGERANT SYSTEM
SERVICE PORT........................2DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................2
DIAGNOSIS AND TESTING - HEATER
PERFORMANCE.......................6
STANDARD PROCEDURE - DIODE
REPLACEMENT.......................6
SPECIFICATIONS
A/C APPLICATION TABLE................7
TORQUE SPECIFICATIONS..............8
CONTROLS.............................9
DISTRIBUTION..........................36
PLUMBING.............................51
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the heating-
air conditioning system, the engine cooling system
must be properly maintained. The use of a bug
screen is not recommended. Any obstructions in front
of the radiator or condenser will reduce the perfor-
mance of the air conditioning and engine cooling sys-
tems.
The engine cooling system includes the heater core
and the heater hoses. Refer to Cooling for more infor-
mation before opening, or attempting any service to
the engine cooling system.
DESCRIPTION - HEATER AND AIR
CONDITIONER
A manual temperature control type heating-air
conditioning system is standard factory-installed
equipment on this model. An electronically controlled
Automatic Zone Control (AZC) type heating-air con-
ditioning system is an available factory-installed
option.
All vehicles are equipped with a common HVAC
housing assembly (Fig. 1). The system combines air
conditioning, heating, and ventilating capabilities in
a single unit housing mounted under the instrument
panel.DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT
The two refrigerant system service ports are used
to charge, recover/recycle, evacuate, and test the air
conditioning refrigerant system. Unique service port
coupler sizes are used on the R-134a system to
ensure that the refrigerant system is not accidentally
contaminated by the use of the wrong refrigerant
(R-12), or refrigerant system service equipment.
Fig. 1 Blend-Air HVAC System - (typical)
1 - Blend Door
2 - Expansion Valve
3 - Evaporator Core
4 - Blower Assembly
5 - Recirculation Door
6 - Evaporator Probe
7 - Heater Core
8 - Heat/Defrost Door
9 - Panel/Defrost Door
WJHEATING & AIR CONDITIONING 24 - 1

DIAGNOSIS AND TESTING - HEATER
PERFORMANCE
Before performing the following tests, refer to Cool-
ing for the procedures to check the radiator coolant
level, serpentine drive belt tension, radiator air flow
and the radiator fan operation. Also be certain that
the accessory vacuum supply line is connected at the
engine intake manifold for the manual temperature
control system.
MAXIMUM HEATER OUTPUT
Engine coolant is delivered to the heater core
through two heater hoses. With the engine idling at
normal operating temperature, set the temperature
control knob in the full hot position, the mode control
switch knob in the floor heat position, and the blower
motor switch knob in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged at the HVAC housing floor
outlets. Compare the test thermometer reading to the
Temperature Reference chart.
Temperature Reference
Ambient Air Temperature15.5É C
(60É F)21.1É C
(70É F)26.6É C
(80É F)32.2É C
(90É F)
Minimum Air Temperature at
Floor Outlet62.2É C
(144É F)63.8É C
(147É F)65.5É C
(150É F)67.2É C
(153É F)
If the floor outlet air temperature is too low, refer
to Cooling to check the engine coolant temperature
specifications. Both of the heater hoses should be hot
to the touch. The coolant return heater hose should
be slightly cooler than the coolant supply heater
hose. If the return hose is much cooler than the sup-
ply hose, locate and repair the engine coolant flow
obstruction in the cooling system. Refer to Cooling
for the procedures.
OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant
flow:
²Pinched or kinked heater hoses.
²Improper heater hose routing.
²Plugged heater hoses or supply and return ports
at the cooling system connections.
²A plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is still
low, a mechanical problem may exist.
MECHANICAL PROBLEMS
Possible locations or causes of insufficient heat:
²An obstructed cowl air intake.
²Obstructed heater system outlets.
²A blend door not functioning properly.
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob(s) on the
A/C Heater control panel, the following could require
service:
²The A/C heater control.
²The blend door actuator(s).
²The wire harness circuits for the A/C heater con-
trol or the blend door actuator(s).²The blend door(s).
²Improper engine coolant temperature.
STANDARD PROCEDURE - DIODE
REPLACEMENT
(1) Disconnect and isolate the negative battery
cable.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 3).
(4) Remove the insulation from the wires in the
harness. Only remove enough insulation to solder in
the new diode.
Fig. 3 DIODE IDENTIFICATION
1 - CURRENT FLOW
2 - BAND AROUND DIODE INDICATES CURRENT FLOW
3 - DIODE AS SHOWN IN THE DIAGRAMS
24 - 6 HEATING & AIR CONDITIONINGWJ
HEATING & AIR CONDITIONING (Continued)

INSTALLATION
(1) Plug the wire harness and/or vacuum harness
connectors into the back of the a/c heater control.
(2) Position the a/c heater control in the instru-
ment panel and secure it with 4 screws. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(3) Reinstall the center upper, and center lower
bezels onto the instrument panel. Refer to Instru-
ment Panel System for the procedures.
(4) Connect the battery negative cable.
A/C PRESSURE TRANSDUCER
DESCRIPTION
The A/C pressure transducer is installed on a fit-
ting located on the refrigerant discharge line near
the condenser. An internally threaded hex fitting on
the transducer connects it to the externally threaded
Schrader-type fitting on the discharge line. A rubber
O-ring seals the connection between the transducer
and the discharge line fitting. Three terminals within
a molded plastic connector receptacle on the top of
the transducer connect it to the vehicle electrical sys-
tem through a take out and connector of the head-
lamp and dash wire harness.
The A/C pressure transducer cannot be adjusted or
repaired and if faulty or damaged, it must be
replaced.
OPERATION
The A/C pressure transducer monitors the pres-
sures in the high side of the refrigerant system
through its connection to a fitting on the discharge
line. The transducer will change its internal resis-
tance in response to the pressures it monitors. The
Powertrain Control Module (PCM) provides a five
volt reference signal and a sensor ground to the
transducer, then monitors the output voltage of the
transducer on a sensor return circuit to determine
refrigerant pressure. The PCM is preporgrammed to
respond to this and other sensor inputs by controlling
the operation of the air conditioning compressor
clutch and the radiator cooling fan to help optimize
air conditioning system performance and to protect
the system components from damage. The A/C pres-
sure transducer input to the PCM will also prevent
the air conditioning compressor clutch from engaging
when the ambient temperatures are below about
0.556É C (33É F) due to the pressure/temperature
relationship of the refrigerant. The Schrader-type
valve in the liquid line fitting permits the A/C pres-
sure transducer to be removed or installed without
distrubing the refrigerant in the system. The A/C
pressure transducer is diagnosed using the DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
Fig. 13 A/C HEATER CONTROL REMOVE/INSTALL
1 - MOUNTING SCREW TABS
Fig. 14 A/C HEATER CONTROL CONNECTIONS
1 - MODE SWITCH
2 - ELECTRICAL CONNECTIONS
3 - VACUUM HARNESS
WJCONTROLS 24 - 25
A/C HEATER CONTROL (Continued)

controlled vehicle accessories during periods of low
engine vacuum such as when the vehicle is climbing
a steep grade, or under other high engine load oper-
ating conditions.
The vacuum reservoir cannot be repaired and, if
faulty or damaged, it must be replaced.
REMOVAL
(1) Remove the right side headlamp mounting
module and headlamp assembly. Refer to Lamps/
Lighting for the procedures.
(2) Remove the two screws that secure the vacuum
reservoir to the base of the radiator closure panel.
(3) Remove the vacuum reservoir.
INSTALLATION
(1) Install the vacuum reservoir in the vehicle and
tighten the two screws to 3.4 N´m (30 in. lbs.).
(2) Install the right side headlamp mounting mod-
ule and headlamp assembly. Refer to Lamps/Lighting
for the procedures.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator probe is a 2 wire temperature sens-
ing element located at the coldest point on the face of
the evaporator. The switch is attached to the evapo-
rator coil fins. The evaporator temperature probe
prevents condensate water on the evaporator coil
from freezing and obstructing A/C system air flow.
OPERATION
The probe is used to switch the clutch OFF before
evaporator freeze-up occurs. Output from the probe is
sampled by the Body Control Module (BCM). The
clutch is switched OFF when the probe temperature
reaches 1.1É C (34É F). It is allowed to switch ON
when the probe temperature reaches 2.2É C (36É F).
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the HVAC housing from the vehi-
cle(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(3) Disassemble the HVAC housing(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - DISASSEMBLY).
(4) Carefully pull the probe out of the evaporator
core.
INSTALLATION
(1) Install the new probe into the evaporator.
NOTE: The new probe must not go into the same
hole (in the evaporator core) that the old probe was
removed from.
(2) Reassemble the HVAC housing(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Reinstall the HVAC assembly in the vehicle(Re-
fer to 24 - HEATING & AIR CONDITIONING/DIS-
TRIBUTION/HVAC HOUSING - INSTALLATION).
(4) Reconnect the battery negative cable.
Fig. 22 VACUUM RESERVOIR
1 - FAN RELAY
2 - SPEED CONTROL SERVO
3 - VACUUM RESERVOIR
WJCONTROLS 24 - 35
VACUUM RESERVOIR (Continued)

REMOVAL - 2.7L TURBO DIESEL
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect the negative battery cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Remove the accessory drive belt from the com-
pressor clutch. Refer to Cooling for the procedure
(Fig. 5).(4) Raise the vehicle on a hoist.
(5) Remove the front splash shield (if equipped).
(6) Remove the (2) refrigerant line retaining bolts
from the compressor. Remove both lines from the
compressor and cover all openings.
(7) Disconnect the compressor clutch electrical con-
nector.
(8) Remove the compressor mounting bolts and
remove the compressor from the vehicle.
Fig. 5 2.7L Diesel Compressor-RHD (LHD typical)
1 - SUCTION LINE MOUNTING SCREW
2 - SUCTION LINE TO H-BLOCK
3 - H-BLOCK
4 - RECEIVER DRIER
5 - LIQUID LINE SERVICE PORT6 - LIQUID LINE AND RECEIVER DRIER
7 - A/C COMPRESSOR
8 - A/C COMPRESSOR DRIVE BELT
9 - RADIATOR - CONDENSOR ASSEMBLY
24 - 60 PLUMBINGWJ
A/C COMPRESSOR (Continued)

STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(8) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(9) Connect the negative battery cable.
A/C CONDENSER
DESCRIPTION
The condenser is located in the air flow in front of
the engine cooling radiator. The condenser is a heat
exchanger that allows the high-pressure refrigerant
gas being discharged by the compressor to give up its
heat to the air passing over the condenser fins.
OPERATION
When the refrigerant gas gives up its heat, it con-
denses. When the refrigerant leaves the condenser, it
has become a high-pressure liquid refrigerant. The
volume of air flowing over the condenser fins is crit-
ical to the proper cooling performance of the air con-
ditioning system. Therefore, it is important that
there are no objects placed in front of the radiator
grille openings in the front of the vehicle or foreign
material on the condenser fins that might obstruct
proper air flow. Also, any factory-installed air seals or
shrouds must be properly reinstalled following radia-
tor or condenser service.
The condenser cannot be repaired and, if faulty or
damaged, it must be replaced.
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS GROUP BEFORE
PERFORMING THE FOLLOWING OPERATION.
CAUTION: Before removing the condenser, note the
location of each of the radiator and condenser air
seals. These seals are used to direct air through the
condenser and radiator. The air seals must be rein-
stalled in their proper locations in order for the air
conditioning and engine cooling systems to per-
form as designed.(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Remove the screws attaching the grille and
headlamp mounting module to the upper crossmem-
ber of the vehicle. Refer to Body for this and further
steps in the procedure.
(4) Remove the headlamps from their mounts.
(5) Remove the nuts that secure the hood latch
and brace to the upper crossmember.
(6) The radiator upper crossmember can be
adjusted left or right through the use of its slotted
mounting holes. Before removal, mark the original
position of the crossmember.
(7) Remove the bolts that secure the radiator to
the upper crossmember and set it aside (Fig. 6).
(8) Remove the engine air filter inlet duct secured
at the headlamp mounting module.
(9) Remove the headlamp mounting module and
front fascia for access to the condenser and fittings.
(10) Disconnect the discharge line and liquid line
refrigerant line fittings from the condenser. Install
plugs in, or tape over all of the opened refrigerant
line fittings.Fig. 6 CONDENSER MOUNTING - TYPICAL
1 - CONDENSER-TO-RADIATOR MOUNTING BRACKETS (2)
2 - UPPER CROSSMEMBER
3 - FAN SHROUD
4 - ALIGNMENT TABS
5 - RADIATOR
6 - ALIGNMENT DOWELS (2)
7 - RUBBER ISOLATORS (2)
8 - RUBBER GROMMETS (2)
9 - LOWER CROSSMEMBER
10 - CONDENSER
24 - 62 PLUMBINGWJ
A/C COMPRESSOR (Continued)