2003 JEEP GRAND CHEROKEE seat

(2) Position the wiper high/low relay in the proper
receptacle in the PDC.
(3) Align the wiper high/low relay terminals with
the terminal cavities in the PDC receptacle.
(4) Push firmly and evenly on the top of the wiper
high/low relay until the terminals are fully seated in
the terminal cavities in the PDC receptacle.
(5) Reinstall the cover onto the PDC.
(6) Reconnect the battery negative cable.
WIPER ON/OFF RELAY
DESCRIPTION
The wiper on/off relay is located in the Power Dis-
tribution Center (PDC) in the engine compartment
near the battery. The wiper on/off relay is a conven-
tional International Standards Organization (ISO)
micro relay (Fig. 28). Relays conforming to the ISO
specifications have common physical dimensions, cur-
rent capacities, terminal patterns, and terminal func-
tions. The relay is contained within a small,
rectangular, molded plastic housing and is connected
to all of the required inputs and outputs by five inte-
gral male spade-type terminals that extend from the
bottom of the relay base.
The wiper on/off relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper on/off relay is an electromechanical
switch that uses a low current input from the Body
Control Module (BCM) to control a high current out-
put to the front wiper motor. The movable common
feed contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The wiper on/off relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Power Distribution Center (PDC).
The inputs and outputs of the wiper on/off relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the common feed termi-
nal of the wiper high/low relay at all times through
the wiper on/off relay output circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Body
Control Module (BCM) through a front wiper on/off
relay control circuit. The BCM controls front wiper
motor operation by controlling a ground path through
this circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a circuit breaker in the Junction Block (JB) through
a fused ignition switch output (run-acc) circuit.
²Normally Open Terminal- The normally open
terminal (87) receives battery current at all times
from a circuit breaker in the Junction Block (JB)
through a fused ignition switch output (run-acc) cir-
cuit, and provides battery current to the front wiper
on/off relay output circuit whenever the relay is ener-
gized.
²Normally Closed Terminal- The normally
closed terminal (87A) is connected to the wiper park
switch in the front wiper motor through the front
wiper park switch sense circuit, and is connected to
the wiper park switch whenever the relay is de-ener-
gized.
The wiper on/off relay can be diagnosed using con-
ventional diagnostic tools and methods.
Fig. 28 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
WJFRONT WIPERS/WASHERS 8R - 31
WIPER HIGH/LOW RELAY (Continued)

DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY
The wiper on/off relay (Fig. 29) is located in the
Power Distribution Center (PDC) in the engine com-
partment near the battery. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
(1) Remove the wiper on/off relay from the PDC.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ON/OFF RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 30).
(3) See the fuse and relay layout label affixed to
the underside of the PDC cover for wiper on/off relay
identification and location.
(4) Remove the wiper on/off relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
(1) See the fuse and relay layout label affixed to
the underside of the PDC cover for the proper wiper
on/off relay location (Fig. 30).
(2) Position the wiper on/off relay in the proper
receptacle in the PDC.
(3) Align the wiper on/off relay terminals with the
terminal cavities in the PDC receptacle.
(4) Push firmly and evenly on the top of the wiper
on/off relay until the terminals are fully seated in the
terminal cavities in the PDC receptacle.
(5) Reinstall the cover onto the PDC.
(6) Reconnect the battery negative cable.
Fig. 29 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 30 Power Distribution Center
1 - RIGHT FENDER
2 - BATTERY
3 - POWER DISTRIBUTION CENTER
4 - COVER
8R - 32 FRONT WIPERS/WASHERSWJ
WIPER ON/OFF RELAY (Continued)

along the left roof side rail to the rear of the vehicle.
At the rear of the vehicle, the headliner hose is
routed above the headliner and along the upper lift-
gate opening panel toward the right side of the vehi-
cle. The headliner hose then passes through a hole
with a rubber grommet in the upper liftgate opening
panel and through another hole with a rubber grom-
met into the upper inner liftgate panel to the rear
washer nozzle.
Washer hose is available for service only as roll
stock, which must then be cut to length. The head-
liner washer hose is integral to the headliner unit
and, if faulty or damaged, the headliner unit must be
replaced. The molded plastic washer hose fittings
cannot be repaired. If these fittings are faulty or
damaged, they must be replaced.
OPERATION
Washer fluid in the washer reservoir is pressurized
and fed by the rear washer pump/motor through the
rear washer system plumbing and fittings to the rear
washer nozzle on the liftgate outer panel above the
liftgate glass. Whenever routing the washer hose or a
wire harness containing a washer hose, it must be
routed away from hot, sharp, or moving parts; and,
sharp bends that might pinch the hose must be
avoided.
REAR WASHER NOZZLE
DESCRIPTION
The rear washer nozzle is a fluidic type unit that
includes an integral check valve (Fig. 3). The nozzle
is constructed of molded plastic and has a rubber
seal and integral snap features on the back of it. The
nozzle is secured by a snap fit in a dedicated mount-
ing hole in the liftgate outer panel above the liftgate
flip-up glass. Within the rear nozzle body, a small
check ball is held against an integral valve seat at
the inlet end of the nozzle by a small coiled spring.
The rear washer nozzle and check valve unit cannot
be adjusted or repaired. If faulty or damaged, the
entire nozzle and check valve unit must be replaced.
OPERATION
The rear washer nozzle is designed to dispense
washer fluid into the wiper pattern area on the out-
side of the liftgate glass. Pressurized washer fluid is
fed to the nozzle from the washer reservoir by the
rear washer pump/motor through a single hose,
which is attached to a barbed nipple on the back of
the rear washer nozzle. The rear washer nozzle
incorporates a fluidic design, which causes the nozzle
to emit the pressurized washer fluid as an oscillating
stream to more effectively cover a larger area of the
glass area to be cleaned. The integral rear nozzle
check valve prevents washer fluid from draining out
of the rear washer supply hoses back to the washer
reservoir. This drain-back would result in a lengthy
delay from when the rear washer switch is actuated
until washer fluid was dispensed through the rear
washer nozzle, because the rear washer pump would
have to refill the rear washer plumbing from the res-
ervoir to the nozzle. The check valve also prevents
washer fluid from siphoning through the rear washer
nozzle after the rear washer system is turned Off.
When the rear washer pump pressurizes and pumps
washer fluid from the reservoir through the rear
washer plumbing, the fluid pressure overrides the
spring pressure applied to the check ball within the
valve and unseats the check ball, allowing washer
fluid to flow to the rear washer nozzle. When the
rear washer pump stops operating, spring pressure
seats the check ball in the valve and fluid flow in
either direction within the rear washer plumbing is
prevented.
REMOVAL
The check valve for the rear washer nozzle is inte-
gral to the nozzle.
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry at the sides of the rear
washer nozzle to release the snap features that
secure it in the mounting hole of the liftgate outer
panel.
Fig. 3 Rear Washer Nozzle
1 - HEADLINER WASHER HOSE
2 - ROOF PANEL
3 - REAR WASHER NOZZLE
4 - LIFTGATE
WJREAR WIPERS/WASHERS 8R - 39
REAR WASHER HOSES/TUBES (Continued)

the washer fluid and forces it through the pump out-
let nipple, the rear washer plumbing, and the rear
washer nozzle onto the liftgate glass.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Raise and support the vehicle.
(3) Remove the liner from the left front fender
wheel house.
(4) Disconnect the left headlamp and dash wire
harness connector for the rear washer pump/motor
from the motor connector receptacle (Fig. 6).
(5) Disconnect the washer hose from the barbed
outlet nipple of the rear washer pump/motor and
allow the washer fluid to drain into a clean container
for reuse.
(6) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the barbed inlet nipple of
the washer pump out of the rubber grommet seal in
the reservoir. Care must be taken not to damage the
reservoir.
(7) Remove the rubber grommet seal from the
washer pump mounting hole in the washer reservoir
and discard.
INSTALLATION
(1) Install a new rubber grommet seal into the
washer pump mounting hole in the washer reservoir.
Always use a new rubber grommet seal on the reser-
voir.(2) Position the barbed inlet nipple of the washer
pump to the rubber grommet seal in the reservoir
(Fig. 6).
(3) Press firmly and evenly on the washer pump
until the barbed inlet nipple is fully seated in the
rubber grommet seal in the washer reservoir mount-
ing hole.
(4) Reconnect the washer hose to the barbed outlet
nipple of the washer pump.
(5) Reconnect the left headlamp and dash wire
harness connector for the rear washer pump/motor
unit to the motor connector receptacle.
(6) Reinstall the liner into the left front fender
wheel house.
(7) Lower the vehicle.
(8) Refill the washer reservoir with the washer
fluid drained from the reservoir during the removal
procedure.
(9) Reconnect the battery negative cable.
REAR WIPER ARM
DESCRIPTION
The rear wiper arm is the rigid member located
between the rear wiper motor output shaft that pro-
trudes from the outer liftgate panel near the base of
the liftgate glass opening and the rear wiper blade
(Fig. 7). This wiper arm features an over-center
hinge that allows easy access to the liftgate and lift-
gate glass for cleaning. The wiper arm has a die cast
metal pivot end. This pivot end has a hole in it with
internal serrations and a plastic pivot cover is
Fig. 6 Washer Pumps (Viewed from Bottom of
Reservoir)
1 - REAR WASHER PUMP/MOTOR
2 - FRONT WASHER PUMP/MOTOR
3 - WASHER FLUID LEVEL SWITCH
Fig. 7 Rear Wiper Arm
1 - LIFTGATE
2 - REAR WIPER MOTOR OUTPUT SHAFT
3 - PARK RAMP
4 - PIVOT COVER
5 - REAR WIPER ARM
6 - NUT
WJREAR WIPERS/WASHERS 8R - 41
REAR WASHER PUMP/MOTOR (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
JUNCTION BLOCK.................... 8W-12-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
ANTILOCK BRAKES................... 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING-HEATER........... 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1
BODY CONTROL MODULE............. 8W-45-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
POWER SUNROOF................... 8W-64-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUT................ 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 WJWIRING 8W - 1

²Ohmmeter - Used to check the resistance
between two points of a circuit. Low or no resistance
in a circuit means good continuity.
CAUTION: Most of the electrical components used
in today's vehicles are Solid State. When checking
resistance in these circuits use a meter with a 10 -
megohm or greater impedance rating. In addition,
make sure the power is disconnected from the cir-
cuit. Circuits that are powered up by the vehicle's
electrical system can cause damage to the equip-
ment and provide false readings.
²Probing Tools - These tools are used for probing
terminals in connectors (Fig. 5). Select the proper
size tool from Special Tool Package 6807, and insert
it into the terminal being tested. Use the other end
of the tool to insert the meter probe.
INTERMITTENT AND POOR CONNECTIONS
Most intermittent electrical problems are caused
by faulty electrical connections or wiring. It is also
possible for a sticking component or relay to cause a
problem. Before condemning a component or wiring
assembly, check the following items.
²Connectors are fully seated
²Spread terminals, or terminal push out
²Terminals in the wiring assembly are fully
seated into the connector/component and locked into
position
²
Dirt or corrosion on the terminals. Any amount of
corrosion or dirt could cause an intermittent problem
²Damaged connector/component casing exposing
the item to dirt or moisture
²Wire insulation that has rubbed through causing
a short to ground
²Some or all of the wiring strands broken inside
of the insulation
²Wiring broken inside of the insulation
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The stepsare listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem area.
(6) Verify the proper operation. For this step,
check for proper operation of all items on the
repaired circuit. Refer to the wiring diagrams.
STANDARD PROCEDURE
STANDARD PROCEDURE - ELECTROSTATIC
DISCHARGE (ESD) SENSITIVE DEVICES
All ESD sensitive components are solid state and a
symbol (Fig. 6) is used to indicate this. When handling
any component with this symbol, comply with the fol-
lowing procedures to reduce the possibility of electro-
static charge build up on the body and inadvertent
discharge into the component. If it is not known
whether the part is ESD sensitive, assume that it is.
(1) Always touch a known good ground before han-
dling the part. This should be repeated while han-
dling the part and more frequently after sliding
across a seat, sitting down from a standing position,
or walking a distance.
(2) Avoid touching electrical terminals of the part,
unless instructed to do so by a written procedure.
(3) When using a voltmeter, be sure to connect the
ground lead first.
(4) Do not remove the part form it's protective
packing until it is time to install the part.
(5) Before removing the part from it's pakage,
ground the pakage to a known good ground on the
vehicle.
Fig. 5 PROBING TOOL
1 - SPECIAL TOOL 6801
2 - PROBING END
Fig. 6 ELECTROSTATIC DISCHARGE SYMBOL
8W - 01 - 8 8W-01 WIRING DIAGRAM INFORMATIONWJ
WIRING DIAGRAM INFORMATION (Continued)

8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch................. 8W-42
A/C Pressure Transducer................ 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Accessory Delay Relay.................. 8W-64
Adjustable Pedals..................... 8W-30
Airbags............................. 8W-43
Ambient Temperature Sensor............ 8W-45
Antennas............................ 8W-47
Ash Receiver Lamp.................... 8W-44
Auto Shut Down Relay................. 8W-30
Automatic Day/Night Mirror............. 8W-49
Automatic Headlamp Light Sensor/VTSS
LED.............................. 8W-39
Automatic Zone Control Module.......... 8W-42
Back-Up Lamp Relay................... 8W-51
Battery Temperature Sensor............. 8W-30
Battery............................. 8W-20
Blend Door Motor/Actuator.............. 8W-42
Blower Motor......................... 8W-42
Body Control Module................... 8W-45
Boost Pressure Sensor.................. 8W-30
Brake Lamp Switch.................... 8W-33
Camshaft Position Sensor............... 8W-30
Capacitors........................... 8W-30
Cargo Lamp.......................... 8W-44
Center High Mounted Stop Lamp......... 8W-51
Cigar Lighter......................... 8W-41
Circuit Breakers...................... 8W-12
Clockspring.................. 8W-33, 41, 43, 47
Coil On Plugs......................... 8W-30
Coil Rail............................. 8W-30
Combination Flasher................... 8W-52
Compact Disc Changer.................. 8W-47
Controller Antilock Brake............... 8W-35
Coolant Level Sensor................... 8W-45
Courtesy Lamps....................... 8W-44
Crankcase Heater..................... 8W-30
Crankshaft Position Sensor.............. 8W-30
Cylinder Lock Switches................. 8W-61
Data Link Connector................... 8W-18
Diagnostic Junction Port................ 8W-18
EGR Solenoid......................... 8W-30
Electric Brake........................ 8W-54
Electronic Speed Control Servo........... 8W-33
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor...... 8W-30
Engine Oil Pressure Sensor.............. 8W-30
Engine Starter Motor................... 8W-21
EVAP/Purge Solenoid................... 8W-30
Fog Lamps........................ 8W-50, 51
Fuel Injectors......................... 8W-30
Fuel Pressure Sensor................... 8W-30Component Page
Fuel Pressure Solenoid................. 8W-30
Fuel Pump........................... 8W-30
Fuel Tank Module..................... 8W-30
Fuses............................ 8W-10, 12
Fusible Link....................... 8W-10, 20
Grounds............................. 8W-15
Generator......................... 8W-20, 30
Glove Box Lamp...................... 8W-44
Glow Plugs........................... 8W-30
Headlamp Leveling Motor............... 8W-50
Heated Seats......................... 8W-63
High Beam Headlamps................. 8W-50
Hood Ajar Switch...................... 8W-39
Horns............................... 8W-41
Hydraulic Cooling Module............ 8W-30, 42
Idle Air Control Motor.................. 8W-30
Ignition Switch....................... 8W-10
Impact Sensors....................... 8W-43
Input Speed Sensor.................... 8W-31
Instrument Cluster.................... 8W-40
Intake Air Temperature Sensor........... 8W-30
Intake Port Swirl Actuator.............. 8W-30
Intrusion Transceiver Module............ 8W-49
Junction Block........................ 8W-12
Knock Sensor......................... 8W-30
Lamp Assemblies................... 8W-51, 52
Leak Detection Pump.................. 8W-30
License Lamps........................ 8W-51
Liftgate............................. 8W-61
Line Pressure Sensor................... 8W-31
Low Beam Headlamps.................. 8W-50
Low Beam Relay...................... 8W-50
Low Beam/Daytime Running Lamp Relay . . . 8W-50
Lumbar Motor........................ 8W-63
Lumbar Switch....................... 8W-63
Manifold Absolute Pressure Sensor........ 8W-30
Manual Temperature Control............. 8W-42
Mass Air Flow Sensor.................. 8W-30
Memory Set Switch................. 8W-62, 63
Mode Door Motor/Actuator............... 8W-42
Multi-Function Switch............... 8W-50, 53
Output Speed Sensor................... 8W-31
Overhead Map/Courtesy Lamp........... 8W-44
Oxygen Sensors....................... 8W-30
Park Brake Switch..................... 8W-40
Park Lamp........................... 8W-50
Park/Neutral Position Switch............ 8W-31
Park/Turn Signal Lamps................ 8W-50
Power Amplifier....................... 8W-47
Power Connector...................... 8W-41
Power Distribution Center............... 8W-10
Power Mirrors........................ 8W-62
WJ8W-02 COMPONENT INDEX 8W - 02 - 1

Component Page
Power Outlet......................... 8W-41
Power Seats.......................... 8W-63
Power Windows....................... 8W-60
Powertrain Control Module.............. 8W-30
Radio............................... 8W-47
Rain Sensor.......................... 8W-49
Recirculation Door Motor/Actuator........ 8W-42
Red Brake Warning Indicator Switch....... 8W-35
Remote Keyless Module................. 8W-39
Remote Radio Switches................. 8W-47
Splices.............................. 8W-10
Seat Belt Switch...................... 8W-43
Seat Module.......................... 8W-63
Sentry Key Immobilizer Module.......... 8W-39
Shifter Assembly...................... 8W-31
Side Impact Sensors................... 8W-43
Side Marker Lamps.................... 8W-50
Side Repeater Lamps................... 8W-52
Siren............................... 8W-49
Speakers............................ 8W-47Component Page
Speed Control Switches................. 8W-33
Sunroof............................. 8W-64
Temperature Valve Actuator............. 8W-42
Throttle Position Sensor................ 8W-30
Trailer Tow.......................... 8W-54
Transfer Case Position Sensor............ 8W-31
Transmission......................... 8W-31
Turn Signal Lamps.................... 8W-52
Underhood Lamp...................... 8W-44
Vehicle Information Center.............. 8W-49
Viscous/Cabin Heater................... 8W-30
Visor/Vanity Lamps.................... 8W-44
Washer Fluid Level Switch.............. 8W-53
Wastegate Solenoid.................... 8W-30
Water In Fuel Sensor................... 8W-30
Wheel Speed Sensors................... 8W-35
Window Defogger...................... 8W-48
Wiper High/Low Relay.................. 8W-53
Wiper Motor.......................... 8W-53
Washer Pump......................... 8W-5
8W - 02 - 2 8W-02 COMPONENT INDEXWJ