2002 JEEP GRAND CHEROKEE relay

(3) Insert the hook formation on the tip of the
wiper arm through the opening in the wiper blade
superstructure ahead of the wiper blade pivot block/
latch unit far enough to engage the pivot block with
the hook (Fig. 10).
(4) Slide the wiper blade pivot block/latch up into
the hook formation on the tip of the wiper arm until
the latch release tab snaps into its locked position.
Latch engagement will be accompanied by an audible
click.
(5) Gently lower the wiper blade onto the glass.
FRONT WIPER MODULE
DESCRIPTION
The front wiper module is secured with four screws
through rubber isolators to the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 11).
The ends of the wiper pivot shafts that protrude
through dedicated openings in the cowl plenum cov-
er/grille panel to drive the wiper arms and blades are
the only visible components of the front wiper mod-
ule. The front wiper module consists of the following
major components:
²Bracket- The front wiper module bracket con-
sists of a long tubular steel main member that has a
stamped pivot bracket formation near each end
where the two wiper pivots are secured. A stamped
steel mounting plate for the wiper motor is secured
with welds near the center of the main member.
²Crank Arm- The front wiper motor crank arm
is a stamped steel unit with a slotted hole on the
driven end that is secured to the wiper motor outputshaft with a nut, and a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the pivot lever
arms. The passenger side drive link has a plastic
socket-type bushing on each end. The driver side
drive link has a plastic socket-type bushing on one
end, and a plastic sleeve-type bushing on the other
end. The socket-type bushing on one end of each
drive link is snap-fit over the ball stud on the lever
arm of its respective pivot. The driver side drive link
sleeve-type bushing end is then fit over the motor
crank arm ball stud, and the other socket-type bush-
ing of the passenger side drive link is snap-fit over
the exposed end of the wiper motor crank arm ball
stud.
²Motor- The front wiper motor is secured with
three screws to the motor mounting plate near the
center of the wiper module bracket. The wiper motor
output shaft passes through a hole in the module
bracket, where a nut secures the wiper motor crank
arm to the motor output shaft. The two-speed perma-
nent magnet wiper motor features an integral trans-
mission, an internal park switch, and an internal
automatic resetting circuit breaker.
²Pivots- The two front wiper pivots are secured
to the ends of the wiper module bracket. The crank
arms that extend from the bottom of the pivot shafts
each have a ball stud on their end. The upper end of
each pivot shaft where the wiper arms will be fas-
tened each has an externally serrated drum with a
threaded stud secured to it.
The front wiper module cannot be adjusted or
repaired. If any component of the module is faulty or
damaged, the entire front wiper module unit must be
replaced. The reinforcement bracket and stud plate
are available for service replacement.OPERATION
The front wiper module operation is controlled by
the battery current inputs received by the wiper
motor from the wiper on/off and wiper high/low
relays. The wiper motor speed is controlled by cur-
rent flow to either the low speed or the high speed
set of brushes. The park switch is a single pole, sin-
gle throw, momentary switch within the wiper motor
that is mechanically actuated by the wiper motor
transmission components. The park switch alter-
nately closes the wiper park switch sense circuit to
ground or to battery current, depending upon the
position of the wipers on the glass. This feature
allows the motor to complete its current wipe cycle
after the wiper system has been turned Off, and to
park the wiper blades in the lowest portion of the
wipe pattern. The automatic resetting circuit breaker
protects the motor from overloads. The wiper motor
Fig. 11 Front Wiper Module
1 - FRONT WIPER MODULE
2 - SCREW (4)
3 - WIRE HARNESS CONNECTOR
4 - LOWER COWL PLENUM PANEL
8R - 16 FRONT WIPERS/WASHERSWJ
FRONT WIPER BLADE (Continued)

the more frequently the RSM will send wipe com-
mands to the BCM to operate the front wiper system.
The RSM operates on battery current received
through a fuse in the Junction Block (JB) on a fused
B(+) circuit. This circuit is switched by the power
accessory (sunroof) delay relay in the JB so that the
RSM will operate whenever the relay is energized by
the BCM. The RSM receives ground at all times
through a take out of the left body wire harness with
an eyelet terminal that is secured by a ground screw
to the front seat crossmember on the floor panel
under the left front seat. It is important to note that
the default condition for the wiper system is auto-
matic wipers Off; therefore, if no message is received
from the RSM by the BCM for more than about five
seconds, the automatic wipers will be disabled and
the BCM will default the front wiper system opera-
tion to the low speed continuous wipe mode.
The RSM ground and battery current inputs can be
diagnosed using conventional diagnostic tools and
methods. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the RSM
internal circuitry, the BCM, the PCI data bus net-
work, or the electronic messages received and trans-
mitted by the RSM over the PCI data bus. The most
reliable, efficient, and accurate means to diagnose
the RSM requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Adjust the inside rear view mirror on the wind-
shield downward far enough to access the lower edge
of the Rain Sensor Module (RSM) trim cover (Fig.
15).
(3) Using a small thin-bladed screwdriver inserted
into the notch at the bottom of trim cover, gently prythe trim cover away from the windshield glass until
it unsnaps from the RSM.
(4) Using a small thin-bladed screwdriver, gently
pry the spring clips on each side of the RSM away
from the bracket on the windshield.
(5) Pull the RSM away from the bracket on the
windshield far enough to access and disconnect the
overhead wire harness connector for the module from
the module connector receptacle.
(6) Remove the RSM from above the inside rear
view mirror.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
Fig. 15 Rain Sensor Module Remove/Install
1 - OVERHEAD CONSOLE
2 - REAR VIEW MIRROR CONNECTOR
3 - BRACKET
4 - REAR VIEW MIRROR BUTTON
5 - SPRING CLIP (2)
6 - RAIN SENSOR MODULE
7 - TRIM COVER
8 - WIRE HARNESS CONNECTOR
WJFRONT WIPERS/WASHERS 8R - 19
RAIN SENSOR MODULE (Continued)

²Continuous Rear Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control sleeve provides one continu-
ous rear wipe switch position.
²Front Washer Mode- The internal circuitry
and hardware of the right (wiper) multi-function
switch control stalk provide front washer system
operation.
²Front Wipe-After-Wash Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control stalk provide a wipe-after-
wash mode.
²Front Wiper Mist Mode- The internal cir-
cuitry and hardware of the right (wiper) multi-func-
tion switch control stalk provide a front wiper system
mist mode.
²Intermittent Front Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control knob provide an intermittent
front wipe mode with five delay interval positions,
except on models equipped with the optional auto-
matic wiper system.
²Intermittent Rear Wipe Mode- The internal
circuitry and hardware of the right (wiper) multi-
function switch control ring provide one fixed inter-
val intermittent rear wipe mode switch position.
²Rear Washer Mode- The internal circuitry and
hardware of the right (wiper) multi-function switch
control stalk provide rear washer system operation.
OPERATION
The right (wiper) multi-function switch uses a com-
bination of resistor multiplexed and conventionally
switched outputs to control the many functions and
features it provides. The switch receives battery cur-
rent on a fused ignition switch output (run-acc) cir-
cuit from a fuse in the Junction Block (JB) whenever
the ignition switch is in the On or Accessory posi-
tions, and receives ground from the Body Control
Module (BCM) on a windshield wiper switch return
circuit. The right (wiper) multi-function switch may
be diagnosed using conventional diagnostic tools and
methods.
Following are descriptions of how the right (wiper)
multi-function switch control stalk operates to control
the functions and features it provides:
²Automatic Wipe Mode- On models equipped
with the optional automatic wiper system, the control
knob on the end of the right (wiper) multi-function
switch control stalk is rotated to one of five minor
intermediate detents to select the desired automatic
wipe sensitivity level. The control knob is rotated
rearward (counterclockwise) to reduce the sensitivity
(increase the interval between wipes), or forward
(clockwise) to increase the sensitivity (decrease the
interval between wipes). The right (wiper) multi-function switch provides a resistor multiplexed out-
put to the Body Control Module (BCM) on a
windshield wiper switch mux circuit. The BCM
responds by sending an electronic message to the
Rain Sensor Module (RSM) over the Programmable
Communications Interface (PCI) data bus indicating
the selected sensitivity level, and by operating the
front wiper system based upon electronic wipe com-
mands received from the RSM over the PCI data bus.
²Continuous Front Wipe Modes- The control
knob on the end of the right (wiper) multi-function
switch control stalk is rotated to an intermediate
detent that is one detent rearward (counterclockwise)
from the full forward (clockwise) detent to select the
low speed continuous front wiper mode, or to its full
forward (clockwise) detent to select the high speed
continuous front wiper mode. For the low speed
mode, the multi-function switch provides a resistor
multiplexed output to the Body Control Module
(BCM) on a windshield wiper switch mux circuit, and
the BCM responds by energizing the wiper on/off
relay in the Power Distribution Center (PDC) for the
front low speed continuous wipe mode. For the high
speed mode, the multi-function switch provides the
same resistor multiplexed output to the BCM on the
windshield wiper switch mux circuit as the low speed
mode, but also provides a ground output to the BCM
on a wiper high control circuit. The BCM responds to
these inputs by energizing the wiper on/off relay and
the wiper high/low relay in the PDC for the front
high speed continuous wipe mode.
²Continuous Rear Wipe Mode- The control
ring on the right (wiper) multi-function switch con-
trol stalk is rotated to the most forward (clockwise)
detent to select the continuous rear wiper mode. The
multi-function switch provides a battery current out-
put to the rear wiper motor on a rear wiper motor
control circuit to signal the rear wiper module to
operate the rear wiper motor in the continuous wipe
mode.
²Front Washer Mode- The control stalk of the
right (wiper) multi-function switch is pulled toward
the steering wheel to momentarily activate the front
washer pump/motor in the front washer mode. The
front washer pump will continue to operate in the
front washer mode until the control stalk is released.
The right (wiper) multi-function switch provides a
battery current output on a washer pump motor
switch output circuit to energize the front washer
pump in the front washer mode.
²Front Wiper Mist Mode- The control stalk of
the right (wiper) multi-function switch is pushed
towards the floor to momentarily activate the front
wiper motor in the mist mode. The front wiper motor
will continue to operate in the mist mode until the
control stalk is released. The right (wiper) multi-
WJFRONT WIPERS/WASHERS 8R - 21
RIGHT MULTI-FUNCTION SWITCH (Continued)

function switch provides a resistor multiplexed out-
put to the Body Control Module (BCM) on a
windshield wiper switch mux circuit, and the BCM
responds by energizing the wiper on/off relay in the
Power Distribution Center (PDC) to operate the front
wiper motor momentarily at low speed to provide the
front wiper mist mode.
²Intermittent Front Wipe Mode- On models
not equipped with the optional automatic wiper sys-
tem, the control knob on the end of the right (wiper)
multi-function switch control stalk is rotated to one
of five minor intermediate detents to select the
desired intermittent front wipe delay interval. The
control knob is rotated rearward (counterclockwise)
to increase the delay, or forward (clockwise) to
decrease the delay. The right (wiper) multi-function
switch provides a resistor multiplexed output to the
Body Control Module (BCM) on a windshield wiper
switch mux circuit. The BCM responds by monitoring
electronic vehicle speed messages received from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus,
then energizing the wiper on/off relay in the Power
Distribution Center (PDC) to operate the front wiper
motor at the proper delay intervals.
²Intermittent Rear Wipe Mode- The control
ring on the right (wiper) multi-function switch con-
trol stalk is rotated to the center detent to select the
intermittent rear wiper mode. The right (wiper)
multi-function switch provides a battery current out-
put to the rear wiper motor on a rear wiper motor
delay control circuit to signal the rear wiper module
to operate the rear wiper in the intermittent wipe
mode.
²Rear Washer Mode- The right (wiper) multi-
function switch control stalk is pushed forward
toward the instrument panel to a momentary posi-
tions to activate the rear washer pump/motor in the
rear washer mode. The rear washer pump will con-
tinue to operate in the rear washer mode until the
control stalk is released. The right (wiper) multi-
function switch provides battery current on a rear
washer pump motor control circuit to energize the
rear washer pump in the rear washer mode.DIAGNOSIS AND TESTING - RIGHT MULTI-
FUNCTION SWITCH
Be certain to perform the diagnosis for the front
wiper system, front washer system, rear wiper sys-
tem, and/or rear washer system before testing the
right multi-function switch. (Refer to 8 - ELECTRI-
CAL/FRONT WIPERS/WASHERS - DIAGNOSIS
AND TESTING) or (Refer to 8 - ELECTRICAL/REAR
WIPERS/WASHERS - DIAGNOSIS AND TESTING).
Refer to the appropriate wiring information. The wir-
ing 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.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE PASSIVE RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG. SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE PASSIVE RESTRAINT
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right multi-function switch from
the steering column and disconnect the instrument
panel wire harness connector for the switch from the
switch connector receptacle.
(3) Using an ohmmeter, check the right multi-func-
tion switch continuity and resistances at the switch
terminals as shown in the Right Multi-Function
Switch test chart (Fig. 17).
8R - 22 FRONT WIPERS/WASHERSWJ
RIGHT MULTI-FUNCTION SWITCH (Continued)

(6) Install and tighten the two screws that secure
the inboard mounting flange of the washer reservoir
to the left inner wheel house. Tighten the screws to
7.4 N´m (66 in. lbs.).
(7) Reconnect the left headlamp and dash wire
harness connectors for the two washer pump/motor
units to the pump/motor unit connector receptacles.
(8) Reinstall the liner into the left front fender
wheel house.
(9) Lower the vehicle.
(10) Install and tighten the one screw that secures
the washer reservoir filler neck to the left inner
fender shield (Fig. 23). Tighten the screw to 7.4 N´m
(66 in. lbs.).
(11) Reinstall the washer reservoir filler cap hinge
onto the hook on the filler neck and close the cap.
(12) Reconnect the two washer reservoir washer
hoses to the two engine compartment washer hoses
at the inline connectors located on the top of the left
front fender wheel house.
(13) Reinstall the air cleaner housing onto the top
of the left front fender wheel house. (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(14) Reconnect the battery negative cable.
WIPER HIGH/LOW RELAY
DESCRIPTION
The wiper high/low relay is located in the Power
Distribution Center (PDC) in the engine compart-
ment near the battery. The wiper high/low relay is a
conventional International Standards Organization
(ISO) micro relay (Fig. 25). Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The relay is contained within a small, rect-
angular, molded plastic housing and is connected to
all of the required inputs and outputs by five integral
male spade-type terminals that extend from the bot-
tom of the relay base.
The wiper high/low relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper high/low 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 high/low 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 high/low relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the output of the wiper
on/off 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 high/
low 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.
Fig. 25 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
WJFRONT WIPERS/WASHERS 8R - 29
WASHER RESERVOIR (Continued)

²Normally Open Terminal- The normally open
terminal (87) is connected to the high speed brush of
the front wiper motor through a front wiper high/low
relay high speed output circuit, and is connected to
the high speed brush whenever the relay is ener-
gized.
²Normally Closed Terminal- The normally
closed terminal (87A) is connected to the low speed
brush of the front wiper motor through a front wiper
high/low relay low speed output circuit, and is con-
nected to the low speed brush whenever the relay is
de-energized.
The wiper high/low relay can be diagnosed using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - WIPER HIGH/LOW
RELAY
The wiper high/low relay (Fig. 26) 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 high/low relay from the
PDC. (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS/WIPER HIGH/LOW RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, andno 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. 27).
(3) See the fuse and relay layout label affixed to
the underside of the PDC cover for wiper high/low
relay identification and location.
(4) Remove the wiper high/low 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
high/low relay location (Fig. 27).
Fig. 26 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 27 Power Distribution Center
1 - RIGHT FENDER
2 - BATTERY
3 - POWER DISTRIBUTION CENTER
4 - COVER
8R - 30 FRONT WIPERS/WASHERSWJ
WIPER HIGH/LOW RELAY (Continued)

(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)