OPERATION
The seat belt tension reducer is controlled by a
ground signal received from the seat belt switch on
the seat belt switch sense circuit and a battery cur-
rent signal received from the ignition switch on the
fused ignition switch output (run-accessory) circuit.
When the seat belt switch is closed (the driver side
front seat belt is fastened) and the ignition switch is
in the On or Accessory positions, the seat belt tension
reducer solenoid is energized. When the solenoid is
energized, it actuates a mechanism within the driver
side front outboard seat belt retractor to reduce the
normal recoil spring tension exerted by the retractor
spool, which is designed to reel in the seat belt web-
bing onto the spool. When the driver side seat belt is
unbuckled or if the ignition switch is turned to any
position except On or Accessory, the tension reducer
solenoid is de-energized and the normal recoil spring
tension of the retractor is restored.
The action of the seat belt tension reducer results
in improved seat belt comfort for the driver. Reducing
the seat belt retractor recoil spring tension is desir-
able on standard cab models of this vehicle and not
on the quad cab model due to the different mounting
position required for the seat belt turning loop on the
B-pillar relative to the driver's seat position on the
standard cab model. The seat belt tension reducer
may be diagnosed using conventional diagnostic tools
and methods.
DIAGNOSIS AND TESTING - SEAT BELT
TENSION REDUCER
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.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the seat belt tension reducer from the tension
reducer connector receptacle on the driver side front
outboard seat belt and retractor unit. Using an ohm-
meter, measure the resistance between the seat belt
switch sense circuit terminal pin and the fused igni-
tion switch output (run-accessory) circuit terminal
pin in the tension reducer connector receptacle on
the retractor. Resistance through the tension reducer
solenoid coil should be 53 ohms at 20É C (68É F). If
OK, go to Step 2. If not OK, replace the faulty driver
side front outboard seat belt and retractor unit.
(2) Check for continuity between the seat belt
switch sense circuit cavity of the body wire harness
connector for the seat belt tension reducer and a good
ground. There should be continuity with the driver
side front seat belt buckled, and no continuity with
the driver side front seat belt unbuckled. If OK, go to
Step 3. If not OK, repair the shorted or open seat
belt switch sense circuit between the tension reducer
and the seat belt switch as required.
(3) Reconnect the battery negative cable. Check for
battery current at the fused ignition switch output
(run-accessory) circuit of the body wire harness con-
nector for the seat belt tension reducer. There should
be battery current with the ignition switch in the On
or Accessory positions, and no battery current with
the ignition switch in any other position. If not OK,
repair the shorted or open fused ignition switch out-
put (run-accessory) circuit between the tension
reducer and the ignition switch as required.
8O - 54 RESTRAINTSDR
SEAT BELT TENSION REDUCER (Continued)
(6) Remove cable from vehicle.
INSTALLATION
3.7L / 4.7L Gas
(1) Install end of cable to speed control servo.
Refer to Servo Removal/Installation.(2) Slide speed control cable plastic mount into
throttle body bracket.
(3) Install speed control cable connector onto throt-
tle body bellcrank pin (push rearward to snap into
location).
(4) Slide throttle (accelerator) cable plastic mount
into throttle body bracket. Continue sliding until
cable release tab is aligned to hole in throttle body
mounting bracket.
(5) While holding throttle to wide open position,
place throttle cable pin into throttle body bellcrank.
(6) Install air intake tube to top of throttle body.
(7) Connect negative battery cable at battery.
(8) Before starting engine, operate accelerator
pedal to check for any binding.
5.9L Diesel Ð Auto. Trans.
(1) Install (connect) end of speed control servo
cable to speed control servo. Refer to Speed Control
Servo Removal/Installation.
(2) Install cable through mounting hole on mount-
ing bracket. Cable snaps into bracket.
(3) Connect servo cable to throttle lever by push-
ing cable connector rearward onto lever pin while
holding lever forward.
(4) Connect negative battery cables to both batter-
ies.
Fig. 3 SPEED CONTROL CABLE AT BELLCRANK -
3.7L / 4.7L
1 - THROTTLE BODY BELLCRANK
2 - SPEED CONTROL CABLE CONNECTOR
Fig. 4 SPEED CONTROL CABLE AT BRACKET - 3.7L
/ 4.7L
1 - THROTTLE CABLE BRACKET
2 - PLASTIC CABLE MOUNT
3 - SPEED CONTROL CABLE
Fig. 5 SERVO CABLE AT THROTTLE LEVER Ð 5.9L
DIESEL
1 - PINCH (2) TABS
2 - CABLE MOUNTING BRACKET
3 - PINCH TABS (2)
4 - OFF
5 - THROTTLE CABLE
6 - THROTTLE LEVER
7 - THROTTLE LEVER PIN
8 - OFF
9 - CONNECTOR
10 - SPEED CONTROL CABLE
DRSPEED CONTROL 8P - 5
CABLE (Continued)
(11) Before starting engine, operate accelerator
pedal to check for any binding.
SWITCH
DESCRIPTION
Two separate switch pods operate the speed control
system. The steering-wheel-mounted switches use
multiplexed circuits to provide inputs to the PCM (to
the ECM for diesel) for ON, OFF, RESUME, ACCEL-
ERATE, SET, DECEL and CANCEL modes. Refer to
the owner's manual for more information on speed
control switch functions and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
Depending on engine control computer (JTEC
having a 3± plug connector or NGC having a 4±
plug connector), 2 types of switches are used.
Both types of switches are internally and exter-
nally different. The switch used with the NGC
system has an attached pigtail lead. The switch
used with the JTEC system does not have an
attached pigtail lead.
OPERATION
When speed control is selected by depressing the
ON, OFF switch, the PCM(ECM for diesel)allows
a set speed to be stored in its RAM for speed control.
To store a set speed, depress the SET switch while
the vehicle is moving at a speed between approxi-
mately 35 and 85 mph. In order for the speed control
to engage, the brakes cannot be applied, nor can the
gear selector be indicating the transmission is in
Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²An indication of Park or Neutral (auto. trans.)
²The VSS signal increases at a rate of 10 mph
per second (indicates that the co-efficient of friction
between the road surface and tires is extremely low)
²Depressing the clutch pedal (manual trans.).
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The VSS signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
²If the actual speed is not within 20 mph of the
set speed
Fig. 6 SPEED CONTROL SERVO LOCATION
1 - BATTERY TRAY
2 - MOUNTING LUGS
3 - SERVO
4 - ELEC. CONNEC.
5 - MOUNTING SCREWS (3)
6 - MOUNTING BRACKET
7 - VACUUM LINE
Fig. 7 SERVO CABLE CLIP REMOVE/INSTALL Ð
TYPICAL
1 - SERVO MOUNTING NUTS (2)
2 - SERVO
3 - CABLE RETAINING CLIP
4 - SERVO CABLE AND SLEEVE
DRSPEED CONTROL 8P - 7
SERVO (Continued)
is secured by integral mounting tabs and a snap fea-
ture to slots in the right side of the cooling module
shroud in the engine compartment. On models with
an optional diesel engine, the washer reservoir is
secured by screws to the back of the upright left ver-
tical member of the radiator support in the engine
compartment. The washer reservoir filler neck is
accessed from the engine compartment.
²Wiper Arm- The two wiper arms are secured
with integral latches to the serrated ends of the two
wiper pivot shafts, which extend through the cowl
plenum cover/grille panel located near the base of the
windshield.
²Wiper Blade- The two wiper blades are
secured to the two wiper arms with an integral latch,
and are parked on the glass near the bottom of the
windshield when the wiper system is not in opera-
tion.
²Wiper High/Low Relay- The wiper high/low
relay is an International Standards Organization
(ISO) micro relay located in the Integrated Power
Module (IPM) in the engine compartment near the
battery.
²Wiper Module- The wiper pivot shafts are the
only visible components of the wiper module. The
remainder of the module is concealed within the cowl
plenum area beneath the cowl plenum cover/grille
panel. The wiper module includes the wiper module
bracket, four rubber-isolated wiper module mounts,
the wiper motor, the wiper motor crank arm, the two
wiper drive links, and the two wiper pivots.
²Wiper On/Off Relay- The wiper on/off relay is
an International Standards Organization (ISO) micro
relay located in the Integrated Power Module (IPM)
in the engine compartment near the battery.
Hard wired circuitry connects the 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 wiper and washer
system components through the use of a combination
of soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
OPERATING MODES
The components of the wiper and washer system
are designed to work in concert to provide the follow-
ing operating modes:²Continuous Wipe Mode- The control knob on
the control stalk of the multi-function switch has two
continuous wipe positions, Low and High. When
selected, these switch positions will cause the two-
speed wiper motor to operate in a continuous low or
high speed cycle.
²Intermittent Wipe Mode- The control knob on
the control stalk of the multi-function switch has five
minor detent intermittent wipe positions. When
selected, these switch positions will cause the wiper
system to operate with one of five delay intervals
between complete wipe cycles. The intermittent wipe
delay intervals are speed sensitive and will be dou-
bled when the vehicle speed is about sixteen kilome-
ters-per-hour (ten miles-per-hour) or less.
²Pulse Wipe Mode- When the control knob on
the control stalk of the multi-function switch is
depressed to the momentary Wash position for less
than about one-half second, the wiper system will
operate the wipers for one complete low speed cycle,
then will park the wiper blades near the base of the
windshield.
²Washer Mode- When the control knob on the
control stalk of the multi-function switch is
depressed to the momentary Wash position for more
than about one-half second with the wiper system
turned Off, the washer pump/motor and the wipers
will operate for as long as the washer switch is held
closed up to about thirty seconds, then the wipe-af-
ter-wash mode is invoked when the control knob is
released. When the Wash position is selected with
the wiper system operating in a continuous wipe
mode, washer fluid will be dispensed onto the wind-
shield glass through the washer nozzles for as long
as the washer switch is held closed up to about thirty
seconds. When the Wash position is selected with the
wiper system operating in an intermittent wipe
mode, washer fluid is still dispensed until the control
knob is released; however, the wipers will operate in
a low speed continuous cycle from the time the
washer switch is closed until several wipe cycles
after the switch is released, before returning to the
selected intermittent wipe interval. If the control
knob is held in the depressed Wash position for more
than about thirty seconds, washer system operation
will be suspended until the control knob is released
for about two seconds then cycled back to the Wash
position.
²Wipe-After-Wash Mode- When the control
knob on the control stalk of the multi-function switch
is depressed to the momentary Wash position for
more than about one-half second with the wiper sys-
tem turned Off, the washer pump/motor and the wip-
ers will operate for as long as the washer switch is
held closed up to about thirty seconds, then provide
several additional wipe cycles after the control knob
DRWIPERS/WASHERS 8R - 3
WIPERS/WASHERS (Continued)
interval at which to de-energize the wiper on/off
relay to complete the wipe-after-wash mode cycle.
DIAGNOSIS AND TESTING - WIPER &
WASHER SYSTEM
If the wiper motor operates, but the wipers do not
move on the windshield, replace the faulty wiper
module. If the washer pump/motor operates, but no
washer fluid is dispensed on the glass; or, if the wip-
ers operate, but chatter, lift, or do not clear the glass,
clean and inspect the wiper and washer system com-
ponents as required. (Refer to 8 - ELECTRICAL/
WIPERS/WASHERS - CLEANING) and (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS - INSPECTION).
For diagnosis and testing of the multi-function
switch (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
DIAGNOSIS AND TESTING). Refer to the appropri-
ate 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 connec-
tors, splices and grounds.
The hard wired circuits and components of the
wiper and washer system may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
instrument cluster, the Front Control Module (FCM),
or the electronic message inputs to or outputs from
the instrument cluster and the FCM that control the
various wiper and washer system operating modes.
The most reliable, efficient, and accurate means to
diagnose the instrument cluster, the FCM, or the
electronic message inputs and outputs related to the
various wiper and washer system operating modes
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
CLEANING - WIPER & WASHER SYSTEM
WIPER SYSTEM
The squeegees of wiper blades exposed to the ele-
ments for a long time tend to lose their wiping effec-
tiveness. Periodic cleaning of the squeegees is
suggested to remove any deposits of salt or road film.
The wiper blades, arms, and windshield glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blades continue to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegees of the
wiper blades from any petroleum-based cleaners,
solvents, or contaminants. These products can rap-
idly deteriorate the rubber squeegees.
WASHER SYSTEM
If the washer system is contaminated with foreign
material, drain the washer reservoir by removing the
washer pump/motor from the reservoir. Clean foreign
material from the inside of the washer pump/motor
inlet filter screen and the washer reservoir using
clean washer fluid, a mild detergent, or a non-abra-
sive cleaner. Flush foreign material from the washer
system plumbing by first disconnecting the washer
hoses from the washer nozzles, then running the
washer pump/motor to run clean washer fluid or
water through the system. Plugged or restricted
washer nozzles should be carefully back-flushed
using compressed air. If the washer nozzle obstruc-
tion cannot be cleared, replace the washer nozzle.
CAUTION: Never introduce petroleum-based clean-
ers, solvents, or contaminants into the washer sys-
tem. These products can rapidly deteriorate the
rubber seals and hoses of the washer system, as
well as the rubber squeegees of the wiper blades.
CAUTION: Never use compressed air to flush the
washer system plumbing. Compressed air pres-
sures are too great for the washer system plumbing
components and will result in further system dam-
age. Never use sharp instruments to clear a
plugged washer nozzle or damage to the nozzle ori-
fice and improper nozzle spray patterns will result.
8R - 6 WIPERS/WASHERSDR
WIPERS/WASHERS (Continued)
reservoir cap. The most visible component of the
washer reservoir is the filler cap unit, which is
secured to and hinges on a hook feature that is inte-
gral to the filler neck near the top of the reservoir.
The bright yellow plastic filler cap snaps over the
filler neck opening and seals the reservoir opening
with an integral rubber gasket. The filler cap is
labeled with an International Control and Display
Symbol icon for ªWindshield Washerº and the text
ªWasher Fluid Onlyº that are molded into it and
highlighted in black against the yellow plastic cap for
visibility.
There are dedicated holes near the bottom of the
rearward facing side of the reservoir provided for the
mounting of the washer pump/motor unit and the
washer fluid level switch. A snap post receptacle
molded into the reservoir allows for mounting of the
washer pump without the use of fasteners. The res-
ervoir also features an integral hose routing trough
on its rearward facing side. Except on models with a
diesel engine, the washer reservoir is secured to the
cooling module radiator shroud with three integral
tabs, two at the bottom and one at the top. The two
bottom tabs are inserted into two slots near the bot-tom of the shroud, while the upper tab slides into an
integral channel-like slot near the top of the shroud.
A molded lock feature on the forward facing surface
of the reservoir engages a molded depression on the
rearward facing surface of the radiator shroud when
the reservoir is fully seated on the shroud, locking
the unit securely in place. On models with a diesel
engine, the washer reservoir is secured with two
screws through integral mounting tabs to the left
vertical member of the radiator support. On many
models, a molded plastic coolant recovery container
or a coolant pressure container must be detached
from the top of the cooling module and moved aside
to access the washer fluid reservoir for service. This
may be accomplished without opening or draining the
engine cooling system.
OPERATION
The washer fluid reservoir provides a secure,
on-vehicle storage location for a large reserve of
washer fluid for operation of the washer system. The
washer reservoir filler neck provides a clearly
marked and readily accessible point from which to
add washer fluid to the reservoir. The washer/pump
motor unit is located in a sump area near the bottom
of the reservoir to be certain that washer fluid will
be available to the pump as the fluid level in the res-
ervoir becomes depleted. The washer pump/motor
unit is mounted in the lowest position in the sump.
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, well before the washer sys-
tem will no longer operate.
REMOVAL
REMOVAL - EXCEPT DIESEL ENGINE
(1) Unlatch and open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the fasteners securing the coolant
recovery container or the coolant pressure container
to the top of the cooling module and move the con-
tainer aside. It is not necessary to open or drain the
engine cooling system. (Refer to 7 - COOLING/EN-
GINE/COOLANT RECOVERY CONTAINER -
REMOVAL) or (Refer to 7 - COOLING/ENGINE/
COOLANT RECOVERY PRESSURE CONTAINER -
REMOVAL).
(4) Disconnect the reservoir washer hose from the
barbed nipple of the inline fitting at the engine com-
partment washer hose in the right headlamp and
dash wire harness and allow the washer fluid to
Fig. 14 Washer Reservoir - except Diesel Engine
1-TOPTAB
2 - HOOK FEATURE
3 - CAP
4 - RESERVOIR
5 - TROUGH
6 - HOSE
7 - LOCK FEATURE
8 - WASHER FLUID LEVEL SWITCH
9 - WASHER PUMP/MOTOR
10 - BOTTOM TAB (2)
DRWIPERS/WASHERS 8R - 15
WASHER RESERVOIR (Continued)
The wiper high/low relay can be diagnosed using
conventional diagnostic tools and methods. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the instrument cluster, the
Front Control Module (FCM), or the electronic mes-
sage inputs to or outputs from the instrument cluster
and the FCM that control the operation of the wiper
high/low relay. The most reliable, efficient, and accu-
rate means to diagnose the wiper high/low relay, the
instrument cluster, the FCM, or the electronic mes-
sage inputs and outputs related to the wiper high/low
relay operation requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - WIPER HIGH/LOW
RELAY
The wiper high/low relay (Fig. 23) is located in the
Integrated Power Module (IPM) 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 IPM.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER HIGH/LOW 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 Integrated Power
Module (IPM) (Fig. 24).
(3) Remove the wiper high/low relay by grasping it
firmly and pulling it straight out from the receptacle
in the IPM.
Fig. 23 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 24 Integrated Power Module
1 - 15 - CARTRIDGE FUSE
16 - 53 - BLADE FUSE
54 - HEATED MIRROR RELAY
55 - WIPER ON/OFF RELAY
56 - A/C CONDENSER FAN RELAY
57 - ENGINE CONTROL RELAY
58 - FUEL PUMP RELAY
59 - TRANSMISSION RELAY
60 - WIPER HIGH/LOW RELAY
61 - SPARE
62 - FOG LAMP RELAY
63 - ADJUSTABLE PEDAL RELAY
64 - A/C CLUTCH RELAY
65 - SPARE
66 - O2 RELAY
67 - SPARE
68 - SPARE
69 - SPARE
70 - SPARE
71 - SPARE
72 - STARTER RELAY
73 - PARK LAMP RELAY
DRWIPERS/WASHERS 8R - 21
WIPER HIGH/LOW RELAY (Continued)
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 Front
Control Module (FCM) to control a high current out-
put to the 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 Integrated Power Module (IPM).
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 Front
Control Module (FCM) through a wiper on/off relay
control circuit. The FCM controls wiper motor opera-
tion by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the IPM 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 fuse in the IPM through a fused ignition
switch output (run-acc) circuit, and provides battery
current to the wiper on/off relay output circuit when-
ever the relay is energized.²Normally Closed Terminal- The normally
closed terminal (87A) is connected to ground at all
times through a take out of the left headlamp and
dash wire harness with an eyelet terminal connector
that is secured by a screw to the front end sheet
metal, and is connected to the wiper on/off relay out-
put circuit whenever the relay is de-energized.
The wiper on/off relay may be diagnosed using con-
ventional diagnostic tools and methods. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the instrument cluster, the
Front Control Module (FCM), or the electronic mes-
sage inputs to or outputs from the instrument cluster
and the FCM that control the operation of the wiper
on/off relay. The most reliable, efficient, and accurate
means to diagnose the wiper on/off relay, the instru-
ment cluster, the FCM, or the electronic message
inputs and outputs related to the wiper on/off relay
operation requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY
The wiper on/off relay (Fig. 28) is located in the
Integrated Power Module (IPM) 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.
Fig. 28 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DRWIPERS/WASHERS 8R - 25
WIPER ON/OFF RELAY (Continued)