2003 JEEP GRAND CHEROKEE Fill location

(5) Install electrical connector to coolant tempera-
ture sensor.
(6) Be sure that the radiator draincock is tightly
closed. Fill the cooling system to the correct levelwith the required coolant mixture (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(7) Start and warm the engine. Check for leaks.
INSTALLATIONÐ4.7L ENGINE
(1) Clean mating areas of timing chain cover and
thermostat housing.
(2) Install thermostat (spring side down) into
recessed machined groove on timing chain cover (Fig.
25).
(3) Position thermostat housing on timing chain
cover.
(4) Install two housing-to-timing chain cover bolts.
Tighten bolts to 13 N´m (115 in. lbs.) torque.
CAUTION: Housing must be tightened evenly and
thermostat must be centered into recessed groove
in timimg chain cover. If not, it may result in a
cracked housing, damaged timing chain cover
threads or coolant leaks.
(5) Install lower radiator hose on thermostat hous-
ing.
(6) Install splash shield.
(7) Lower vehicle.
(8) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(9) Connect negative battery cable to battery.
(10) Start and warm the engine. Check for leaks.
Fig. 25 Thermostat and Thermostat Housing
1 - THERMOSTAT HOUSING
2 - THERMOSTAT LOCATION3 - THERMOSTAT AND GASKET
4 - TIMING CHAIN COVER
Fig. 26 Thermostat Recess
1 - GROOVE
WJENGINE 7 - 39
ENGINE COOLANT THERMOSTAT (Continued)

INSPECTION
The radiator cooling fins should be checked for
damage or deterioration. Inspect cooling fins to make
sure they are not bent or crushed, these areas result
in reduced heat exchange causing the cooling system
to operate at higher temperatures. Inspect the plastic
end tanks for cracks, damage or leaks.
Inspect the radiator neck for damage or distortion.
INSTALLATION
CAUTION: Before installing the radiator or A/C con-
denser, be sure the radiator-to-body and radiator-to-
A/C condenser rubber air seals (Fig. 39) are
properly fastened to their original positions. These
are used at the top, bottom and sides of the radia-
tor and A/C condenser. To prevent overheating,
these seals must be installed to their original posi-
tions.
(1) Equipped with air conditioning: Gently lower
the radiator into the vehicle. Guide the two radiator
alignment dowels through the holes in the rubber air
seals first and then through the A/C support brackets
(Fig. 40). Continue to guide the alignment dowels
into the rubber grommets located in lower radiator
crossmember. The holes in the L-shaped brackets
(located on bottom of A/C condenser) must be posi-
tioned between bottom of rubber air seals and top of
rubber grommets.
(2) Connect the radiator upper and lower hoses
and hose clamps to radiator (Fig. 41).
CAUTION: The tangs on the hose clamps must be
positioned straight down.
(3) Install coolant reserve/overflow tank hose at
radiator (Fig. 41).
(4) Connect both transmission cooler lines at the
radiator (Fig. 41).
(5) Install both radiator mounting bolts (Fig. 41).
(6) Install air inlet duct at grill.
(7) Attach electric fan harness to shroud, then con-
nect harness to connector (Fig. 41).
(8) Install the grill (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION).
(9) Install the fan/viscous fan drive assembly to
the water pump.
(10) Rotate the fan blades (by hand) and check for
interference at fan shroud.
(11) Be sure of at least 25 mm (1.0 inch) between
tips of fan blades and fan shroud.
(12) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(13) Connect battery cable at battery.
(14) Start and warm engine. Check for leaks.
RADIATOR FAN MOTOR
DIAGNOSIS AND TESTINGÐELECTRIC
COOLING FAN
The powertrain control module (PCM) will enter a
diagnostic trouble code (DTC) in memory if it detects
a problem in the auxiliary cooling fan relay or circuit.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
If the electric cooling fan is inoperative, check the
15A fuse in the junction block and the 40A fuse in
the Power Distribution Center (PDC) with a 12 volt
test lamp or DVOM. Refer to the inside of the PDC
cover for the exact location of the fuse. If fuses are
okay, refer to ELECTRICAL for cooling fan and relay
circuit schematic.
WATER PUMP - 4.7L
DESCRIPTION
DESCRIPTIONÐWATER PUMP
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a
single serpentine drive belt.
The water pump impeller is pressed onto the rear
of a shaft that rotates in bearings pressed into the
housing. The housing has two small holes to allow
seepage to escape. The water pump seals are lubri-
cated by the antifreeze in the coolant mixture. No
additional lubrication is necessary.
Both heater hoses are connected to fittings on the
timing chain front cover. The water pump is also
mounted directly to the timing chain cover and is
equipped with a non serviceable integral pulley (Fig.
42).
DESCRIPTIONÐWATER PUMP BYPASS
The 4.7L engine uses an internal water/coolant
bypass system. The design uses galleries in the tim-
ing chain cover to circulate coolant during engine
warm-up preventing the coolant from flowing
through the radiator. The thermostat uses a stub
shaft located at the rear of the thermostat (Fig. 43)
to control flow through the bypass gallery.
OPERATION
OPERATIONÐWATER PUMP
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
WJENGINE 7 - 47
RADIATOR - 4.0L (Continued)

INSPECTION
Visually inspect the pressure valve gasket on the
cap. Replace cap if the gasket is swollen, torn or
worn. Inspect the area around radiator filler neck for
white deposits that indicate a leaking cap.
WATER PUMP INLET TUBE
REMOVAL
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 52). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 53). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
(1) Partially drain cooling system .
(2) Do not waste reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.(3) Loosen both bypass hose clamps (Fig. 52) and
position to center of hose. Remove hose from vehicle.
INSTALLATION
(1) Position bypass hose clamps (Fig. 52) to center
of hose.
(2) Install bypass hose to engine.
(3) Secure both hose clamps (Fig. 52).
(4) Refill cooling system .
(5) Start and warm the engine. Check for leaks.
Fig. 51 Pressure Testing Radiator Pressure
CapÐTypical
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
Fig. 52 Hose Clamp ToolÐTypical
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 53 Clamp Number/Letter Location
1 - TYPICAL CONSTANT TENSION HOSE CLAMP
2 - CLAMP NUMBER/LETTER LOCATION
3 - TYPICAL HOSE
7 - 54 ENGINEWJ
RADIATOR PRESSURE CAP (Continued)

OPERATION
Although cylinder firing order is the same as 4.0L
Jeep engines of previous years, spark plug firing is
not. The 3 coils dual-fire the spark plugs on cylinders
1-6, 2-5 and/or 3-4. When one cylinder is being fired
(on compression stroke), the spark to the opposite
cylinder is being wasted (on exhaust stroke).
Battery voltage is supplied to the three ignition
coils from the ASD relay. The Powertrain Control
Module (PCM) opens and closes the ignition coil
ground circuit for ignition coil operation.
Base ignition timing is not adjustable.By con-
trolling the coil ground circuit, the PCM is able to set
the base timing and adjust the ignition timing
advance. This is done to meet changing engine oper-
ating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
Because of coil design, spark plug cables (second-
ary cables) are not used. The cables are integral
within the coil rail.
REMOVAL
A one-piece coil rail assembly containing three
individual coils is used on the 4.0L engine (Fig. 13).
The coil rail must be replaced as one assembly. The
bottom of the coil is equipped with 6 individual rub-
ber boots (Fig. 13) to seal the 6 spark plugs to the
coil. Inside each rubber boot is a spring. The spring
is used for an electrical contact between the coil and
the top of the spark plug. These rubber boots and
springs are a permanent part of the coil and are not
serviced separately.
(1) Disconnect negative battery cable at battery.
(2) The coil is bolted directly to the cylinder head.
Remove 4 coil mounting bolts (Fig. 14).
(3) Carefully pry up coil assembly from spark
plugs. Do this by prying alternately at each end of
coil until rubber boots have disengaged from all
spark plugs. If boots will not release from spark
plugs, use a commercially available spark plug boot
removal tool. Twist and loosen a few boots from a few
spark plugs to help remove coil.
(4) After coil has cleared spark plugs, position coil
for access to primary electrical connector. Disconnect
connector from coil by pushing slide tab outwards to
right side of vehicle (Fig. 15). After slide tab has been
positioned outwards, push in on secondary release
lock (Fig. 15) on side of connector and pull connector
from coil.
(5) Remove coil from vehicle.
Fig. 13 Ignition Coil AssemblyÐ4.0L 6±Cylinder
Engine
1 - CYL. #6
2 - CYL. #5
3 - CYL. #4
4 - CYL. #3
5 - CYL. #2
6 - CYL. #1
7 - COILS (3)
8 - MOUNTING BOLTS (4)
9 - BOLT BASES (4)
10 - RUBBER BOOTS (6)
Fig. 14 Ignition Coil Rail LocationÐ4.0L 6±Cylinder
Engine
1 - COIL RAIL
2 - COIL MOUNTING BOLTS (4)
3 - COIL
4 - COIL ELECTRICAL CONNECTION
8I - 10 IGNITION CONTROLWJ
COIL RAIL (Continued)

FUEL GAUGE
DESCRIPTION
A fuel gauge is standard equipment on all instru-
ment clusters. The fuel gauge is located in the lower
left corner of the instrument cluster, to the left of the
tachometer. The fuel gauge consists of a movable
gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 90 degree scale on the
gauge dial face that reads left-to-right from E (or
Empty) to F (or Full). An International Control and
Display Symbol icon for ªFuelº is located on the
gauge dial face. An arrowhead pointed to the left side
of the vehicle is imprinted next to the ªFuelº icon on
the fuel gauge dial face to provide the driver with a
reminder as to the location of the fuel filler access.
The fuel gauge graphics are either white, gray and
orange against a black gauge dial face (base cluster)
or black and gray against a taupe gauge dial face
(premium cluster), making them clearly visible
within the instrument cluster in daylight. When illu-
minated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-
rior lamps turned On, the base cluster white gauge
graphics appear blue-green and the orange graphics
still appear orange, while the premium cluster taupe
gauge dial face appears blue-green with the black
graphics silhouetted against the illuminated back-
ground. The gray gauge graphics for both versions of
the cluster are not illuminated. The orange gauge
needle in the base cluster gauge is internally illumi-
nated, while the black gauge needle in the premium
cluster gauge is not.
Base cluster gauge illumination is provided by
replaceable incandescent bulb and bulb holder units
located on the instrument cluster electronic circuit
board. Premium cluster gauge illumination is pro-
vided by an integral electro-luminescent lamp that is
serviced as a unit with the instrument cluster. The
fuel gauge is serviced as a unit with the instrument
cluster.
OPERATION
The fuel gauge gives an indication to the vehicle
operator of the level of fuel in the fuel tank. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
fuel gauge is an air core magnetic unit that receives
battery current on the instrument cluster electronic
circuit board through the fused ignition switch out-
put (run-start) circuit whenever the ignition switch is
in the On or Start positions. The cluster is pro-
grammed to move the gauge needle back to the lowend of the scale after the ignition switch is turned to
the Off position. The instrument cluster circuitry
controls the gauge needle position and provides the
following features:
²Percent Tank Full Message- Each time the
cluster receives a message from the PCM indicating
the percent tank full, the cluster moves the gauge
needle to the relative fuel level position on the gauge
scale. The PCM applies an algorithm to the input
from the fuel tank sender to dampen gauge needle
movement against the negative effect that fuel slosh-
ing within the fuel tank can have on accurate inputs
to the PCM.
²Less Than 12.5 Percent Tank Full Message-
Each time the cluster receives messages from the
PCM indicating the percent tank full is less than
12.5 (one-eighth), the gauge needle is moved to the
proper position on the gauge scale and the low fuel
indicator is illuminated. The low fuel indicator
remains illuminated until the cluster receives mes-
sages from the PCM indicating that the percent tank
full is greater than 12.5 (one-eighth), or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Less Than Empty Percent Tank Full Mes-
sage- Each time the cluster receives a message from
the PCM indicating the percent tank full is less than
empty, the gauge needle is moved to the far left (low)
end of the gauge scale and the low fuel indicator is
illuminated immediately. This message would indi-
cate that the fuel tank sender input to the PCM is a
short circuit.
²More Than Full Percent Tank Full Message
- Each time the cluster receives a message from the
PCM indicating the percent tank full is more than
full, the gauge needle is moved to the far left (low)
end of the gauge scale and the low fuel indicator is
illuminated immediately. This message would indi-
cate that the fuel tank sender input to the PCM is an
open circuit.
²Communication Error- If the cluster fails to
receive a percent tank full message, it will hold the
gauge needle at the last indication for about twelve
seconds, until a new message is received, or until the
ignition switch is turned to the Off position, which-
ever occurs first. After twelve seconds, the cluster
will return the gauge needle to the low end of the
gauge scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept across the entire gauge scale and back in order
to confirm the functionality of the gauge and the
cluster control circuitry.
The PCM continually monitors the fuel tank
sender to determine the fuel level. The PCM then
applies an algorithm to the input and sends the
WJINSTRUMENT CLUSTER 8J - 21

²Front Check Valve- The front washer system
check valve is integral to the wye fitting located in
the washer plumbing between the cowl plenum
washer hose and the front washer nozzles, and is
concealed beneath the cowl plenum cover/grille panel
at the base of the windshield.
²Front Washer Nozzle- Two fluidic front
washer nozzles are secured with integral snap fea-
tures to dedicated openings in the cowl plenum cover/
grille panel located near the base of the windshield.
²Front Washer Plumbing- The plumbing for
the front washer system consists of rubber hoses and
molded plastic fittings. The plumbing is routed along
the left side of the engine compartment from the
washer reservoir, and through the dash panel into
the cowl plenum to the front washer nozzle fittings
beneath the cowl plenum cover/grille panel.
²Front Washer Pump/Motor- The front washer
pump/motor unit is located in a dedicated hole on the
lower outboard side of the washer reservoir, behind
the inner fender liner ahead of the left front wheel.
The front washer pump is located ahead of and below
the rear washer pump.
²Front Wiper Arm- The two front wiper arms
are secured with nuts to the threaded studs on the
ends of the two wiper pivot shafts, which extend
through the cowl plenum cover/grille panel located
near the base of the windshield.
²Front Wiper Blade- The two front wiper
blades are secured to the two front wiper arms with
an integral latch, and are parked on the glass near
the bottom of the windshield when the front wiper
system is not in operation.
²Front Wiper Module- The front wiper pivot
shafts are the only visible components of the front
wiper module. The remainder of the module is con-
cealed within the cowl plenum beneath the cowl ple-
num cover/grille panel. The front wiper module
includes the module bracket, four rubber-isolated
wiper module mounts, the front wiper motor, the
wiper motor crank arm, the two wiper drive links,
and the two front wiper pivots.
²Rain Sensor Module- Models equipped with
the optional automatic wiper feature have a Rain
Sensor Module (RSM) located behind a trim cover on
a bracket bonded to the inside surface of the wind-
shield glass, just above the inside rear view mirror
mounting button.
²Right Multi-Function Switch- The right
(wiper) multi-function switch is secured to the right
side of the multi-function switch mounting housing
near the top of the steering column, just below the
steering wheel. Only the control stalk for the right
multi-function switch is visible, while the remainder
of the switch is concealed beneath the steering col-
umn shrouds. The right multi-function switch con-tains all of the switches and control circuitry for both
the front and rear wiper and washer systems.
²Washer Fluid Level Switch- The washer fluid
level switch is located in a dedicated hole near the
center of the forward surface of the washer reservoir,
behind the left front wheel house splash shield.
²Washer Reservoir- The washer reservoir is
concealed between the left inner fender shield and
the left outer fender panel, behind the inner fender
liner and ahead of the left front wheel. The washer
reservoir filler neck is the only visible portion of the
reservoir, and it is accessed from the left front corner
of the engine compartment.
²Wiper High-Low Relay- The wiper high-low
relay is an International Standards Organization
(ISO) micro relay located in the Power Distribution
Center (PDC) in the engine compartment near the
battery.
²Wiper On-Off Relay- The wiper on-off relay is
an International Standards Organization (ISO) micro
relay located in the Power Distribution Center (PDC)
in the engine compartment near the battery.
Hard wired circuitry connects the front wiper and
washer system components to the electrical system of
the vehicle. These hard wired circuits are integral to
several wire harnesses, which are routed throughout
the vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the front wiper and
washer system components through the use of a com-
bination of soldered splices, splice block connectors,
and many different types of wire harness terminal
connectors and insulators. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.
OPERATING MODES
The components of the front wiper and washer sys-
tem are designed to work in concert to provide the
following operating modes:
²Automatic Wiper- In models equipped with
the optional automatic wiper feature, the internal
circuitry of both the right (wiper) multi-function
switch, the rain sensor module, and the BCM work
in concert to provide an automatic wiper mode with
five sensitivity selections. The BCM tells the Rain
Sensor Module (RSM) when the automatic wiper
mode is selected and the manually selected sensitiv-
ity level, then the rain sensor module tells the BCM
each time enough water droplets have accumulated
within the wipe pattern on the windshield to require
front wiper operation. The BCM then automatically
WJFRONT WIPERS/WASHERS 8R - 3
FRONT WIPERS/WASHERS (Continued)

WASHER RESERVOIR
DESCRIPTION
A single washer fluid reservoir is used for both the
front and rear washer systems (Fig. 22). The molded
plastic washer fluid reservoir is concealed between
the left front inner and outer fender panels, behind
the inner fender liner in front of the left front wheel.
The only visible component of the washer reservoir is
the filler neck and cap unit, which extends through a
hole in the left front wheel house extension panel
into the engine compartment. A bright yellow plastic
filler cap with a rubber seal and an International
Control and Display Symbol icon for ªWindshield
Washerº and the text ªWasher Fluid Onlyº molded
into it snaps over the open end of the filler neck. The
cap hinges on and is secured to a molded-in hook for-
mation on the rear of the reservoir filler neck.There are separate, dedicated holes on the out-
board side of the reservoir provided for the mounting
of the front and rear washer/pump motor units, and
another dedicated hole on the front of the reservoir
for the washer fluid level switch. The inboard side of
the washer reservoir has an integral flange that is
secured to the inside of the left front fender wheel
house by two screws, while an integral molded tab
engages a slot in the left front fender inner shield to
support the outboard side of the reservoir. Another
screw secures the reservoir filler neck to the left
front fender inner shield near the front of the engine
compartment. The left front fender wheel house
inner liner must be removed to access the washer
reservoir for service.
The washer reservoir cannot be repaired and, if
faulty or damaged, it must be replaced. The washer
reservoir, the grommet seals for the washer pump/
motor units and the washer fluid level switch, and
the filler cap are each available for service replace-
ment.
OPERATION
The washer fluid reservoir provides a secure,
on-vehicle storage location for a large reserve of
washer fluid for operation of the front and rear
washer systems. The washer reservoir filler neck pro-
vides a clearly marked and readily accessible point
from which to add washer fluid to the reservoir. The
front and rear washer/pump motor units are located
in a sump area near the front of the reservoir to be
certain that washer fluid will be available to the
pumps as the fluid level in the reservoir becomes
depleted. The front washer pump/motor unit is
mounted in the lowest position in the sump so that
the front washers will operate even after the rear
washer system will no longer operate. The washer
fluid level switch is mounted just above the sump
area of the reservoir so that there will be adequate
warning to the vehicle operator that the washer fluid
level is low, before the washer system will no longer
operate.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the air cleaner housing from the top of
the left front fender wheel house. (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
Fig. 22 Washer Reservoir
1 - LEFT FENDER INNER SHIELD
2 - SCREW (2)
3 - WASHER PUMP WIRE HARNESS CONNECTORS
4 - WASHER FLUID LEVEL SWITCH WIRE HARNESS
CONNECTOR
5 - WASHER RESERVOIR
WJFRONT WIPERS/WASHERS 8R - 27

²Washer Reservoir- The rear washer system
shares a single reservoir with the front washer sys-
tem, but has its own dedicated washer pump/motor
and plumbing. The washer reservoir is concealed
between the left inner fender shield and the left
outer fender panel, behind the inner fender liner and
ahead of the left front wheel. The washer reservoir
filler neck is the only visible portion of the reservoir,
and it is accessed from the left front corner of the
engine compartment.
Features of the rear wiper and washer system
include the following:
²Continuous Wipe Mode- When the right
multi-function switch control sleeve is moved to the
On position, the rear wiper will be operated at a
fixed speed, continual wipe cycle until the switch
sleeve is moved to the Delay or Off positions, until
the ignition switch is turned to the Off position, or
until the liftgate flip-up glass is ajar.
²Intermittent Wipe Mode- When the right
multi-function switch control sleeve is moved to the
Delay position, the rear wiper will be operated in a
fixed interval, intermittent wipe cycle until the
switch sleeve is moved to the On or Off positions,
until the ignition switch is turned to the Off position,
until the liftgate flip-up glass is ajar, or until the
right multi-function switch control stalk is pushed
forward to activate the rear washer system. The
intermittent wipe mode delay time has a fixed delay
interval of about five to eight seconds between
sweeps.
²Washer Mode- When the right multi-function
switch control stalk is pushed forward to activate the
rear washer system, washer fluid will be dispensed
from the washer reservoir onto the liftgate glass
through the rear washer nozzle and the rear wiper
will operate in a fixed cycle (not intermittent) for as
long as the rear washer pump/motor unit remains
energized. When the control stalk is released from
the momentary Wash position, the wipe-after-wash
feature will continue to operate the rear wiper at a
fixed cycle for about three additional wiper sweeps
before returning to the previously selected mode.
Hard wired circuitry connects the rear wiper and
washer system components to the electrical system of
the vehicle. These hard wired circuits are integral to
several wire harnesses, which are routed throughout
the vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the rear wiper and
washer system components through the use of a com-
bination of soldered splices, splice block connectors,
and many different types of wire harness terminal
connectors and insulators. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repairprocedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.
OPERATION
The rear wiper and washer system is intended to
provide the vehicle operator with a convenient, safe,
and reliable means of maintaining visibility through
the liftgate glass. The various components of this sys-
tem are designed to convert electrical energy pro-
duced by the vehicle electrical system into the
mechanical action of the wiper blade to wipe the out-
side surface of the glass, as well as into the hydraulic
action of the washer system to apply washer fluid
stored in an on-board reservoir to the area of the
glass to be wiped. When combined, these components
provide the means to effectively maintain clear visi-
bility for the vehicle operator by removing excess
accumulations of rain, snow, bugs, mud, or other
minor debris from the outside liftgate glass surface
that might be encountered while driving the vehicle
under numerous types of inclement operating condi-
tions. The vehicle operator initiates all rear wiper
and washer system functions with the right multi-
function switch located on the right side of the steer-
ing column, just below the steering wheel. Moving
the switch control sleeve to a detent position selects
the rear wiper system operating mode. Moving the
switch control stalk forward to a momentary position
activates the rear washer pump/motor, which dis-
penses washer fluid onto the liftgate glass through
the rear washer nozzle and operates the rear wiper
system in the fixed cycle mode for as long as the
washer switch is closed plus about three wiper
sweeps.
When the ignition switch is in the Accessory or On
positions, battery current from a fuse in the Junction
Block (JB) is provided to the right multi-function
switch through a fused ignition switch output (run-
acc) circuit. A separate fuse in the JB provides bat-
tery current to the electronic control circuitry of the
rear wiper module through a fused B(+) circuit.
When the right multi-function switch control sleeve
On position is selected, the On position circuitry
within the switch directs a battery current rear
wiper motor control signal input to the rear wiper
module electronic circuitry, which causes the rear
wiper motor to run at a fixed continuous wipe cycle.
When the right multi-function switch control sleeve
Delay position is selected, the Delay position cir-
cuitry within the switch directs a battery current
rear washer switch output signal input to the rear
wiper module electronic circuitry, which causes the
rear wiper motor to run at a fixed intermittent wipe
cycle. When the right multi-function switch control
8R - 34 REAR WIPERS/WASHERSWJ
REAR WIPERS/WASHERS (Continued)