1998 DODGE RAM 1500 system

is released before parking the wiper blades near the
base of the windshield. If the control knob is held in
the depressed Wash position for more than about
thirty seconds, washer system operation will be sus-
pended until the control knob is released for about
two seconds then cycled back to the Wash position.
OPERATION
The wiper and washer system is designed to pro-
vide the vehicle operator with a convenient, safe, and
reliable means of maintaining visibility through the
windshield 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 blades to wipe the
outside 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 main-
tain clear visibility for the vehicle operator by remov-
ing excess accumulations of rain, snow, bugs, mud, or
other minor debris from the outside windshield glass
surface that might be encountered while driving the
vehicle under numerous types of inclement operating
conditions.
The vehicle operator initiates all wiper and washer
system functions with the control knob on the end of
the control stalk of the multi-function switch that
extends from the left side of the steering column, just
below the steering wheel. Rotating the control knob
on the end of the control stalk, selects the Off, Delay,
Low, or High wiper system operating modes. In the
Delay mode, the control knob also allows the vehicle
operator to select from one of five intermittent wipe
Delay intervals. Depressing the control knob towards
the steering column actuates the momentary washer
system switch, which selects the Wash, Wipe-After-
Wash, and Pulse Wipe Modes depending upon when
and how long the switch is held closed. The multi-
function switch provides hard wired resistor multi-
plexed inputs to the instrument cluster for all of the
wiper and washer system functions. The instrument
cluster then sends electronic messages to the Front
Control Module (FCM) over the Programmable Com-
munications Interface (PCI) data bus requesting the
appropriate wiper and washer system operating
modes.
Wiper and washer system operation are completely
controlled by the instrument cluster and FCM logic
circuits, and that logic will only allow these systems
to operate when the ignition switch is in the Acces-
sory or On positions. Battery current is directed from
a B(+) fuse in the Integrated Power Module (IPM) to
the wiper on/off relay and the wiper high/low relay in
the IPM through a fused B(+) circuit. The FCM useslow side drivers to control wiper system operation by
energizing or de-energizing the wiper high/low and
wiper on/off relays. The FCM uses a high side driver
to control the operation of the washer pump motor
unit. The multi-function switch circuitry receives a
clean ground output from the instrument cluster on a
multi-function switch return circuit, then provides
resistor multiplexed inputs to the instrument cluster
on an intermittent wipe mux circuit to indicate the
selected wiper system mode and on a wash/beam
select mux circuit to indicate the selected washer sys-
tem mode.
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 FCM, or the electronic mes-
sage inputs to or outputs from the instrument cluster
or FCM that control the wiper and washer system
operating modes. The most reliable, efficient, and
accurate means to diagnose the instrument cluster or
the FCM inputs and outputs related to the various
wiper and washer system operating modes requires
the use of a DRBIIItscan tool. Refer to the appro-
priate diagnostic information.
OPERATING MODES
Following are paragraphs that briefly describe the
operation of each of the wiper and washer system
operating modes.
CONTINUOUS WIPE MODE
When the Low position of the control knob on the
control stalk of the multi-function switch is selected
the instrument cluster sends an electronic wiper
switch low message to the FCM, then the FCM ener-
gizes the wiper on/off relay. This directs battery cur-
rent through the normally open contacts of the
energized wiper on/off relay and the normally closed
contacts of the de-energized wiper high/low relay to
the low speed brush of the wiper motor, causing the
wipers to cycle at low speed.
When the High position of the control knob is
selected the instrument cluster sends an electronic
wiper switch high message to the FCM, then the
FCM energizes both the wiper on/off relay and the
wiper high/low relay. This directs battery current
through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speed
brush of the wiper motor, causing the wipers to cycle
at high speed.
When the Off position of the multi-function switch
control knob is selected, the instrument cluster sends
an electronic wiper switch off message to the FCM. If
8R - 4 WIPERS/WASHERSDR
WIPERS/WASHERS (Continued)

the wiper motor was operating at high speed, the
FCM immediately de-energizes the wiper high/low
relay causing the wiper motor to return to low speed
operation. Then one of two events will occur. The
event that occurs depends upon the position of the
wiper blades on the windshield at the moment that
the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the wiper motor is
closed to ground and provides a hard wired park
switch sense input to the FCM. The FCM then de-en-
ergizes the wiper on/off relay and the wiper motor
ceases to operate. If the wiper blades are not in the
down position on the windshield at the moment the
Off position is selected, the park switch is an open
circuit and the FCM keeps the wiper on/off relay
energized, which causes the wiper motor to continue
running at low speed until the wiper blades are in
the down position on the windshield and the park
switch input to the FCM is again closed to ground.
INTERMITTENT WIPE MODE
When the control knob on the control stalk of the
multi-function switch is moved to one of the Delay
interval positions the instrument cluster sends an
electronic wiper switch delay message to the FCM,
then the FCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The FCM monitors the changing
state of the wiper motor park switch through a hard
wired park switch sense input. This input allows the
FCM to determine the proper intervals at which to
energize and de-energize the wiper on/off relay to
operate the wiper motor intermittently for one low
speed cycle at a time.
The FCM logic is also programmed to provide vehi-
cle speed sensitivity to the selected intermittent wipe
delay intervals. In order to provide this feature the
FCM monitors electronic vehicle speed messages
from the Powertrain Control Module (PCM) and dou-
bles the selected delay interval whenever the vehicle
speed is about sixteen kilometers-per-hour (ten miles-
per-hour) or less.
PULSE 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 instrument cluster sends an electronic washer
switch message to the FCM, then the FCM the ener-
gizes the wiper on/off relay for one complete wipe
cycle. The FCM de-energizes the relay when the state
of the park switch sense changes to ground, parking
the wiper blades near the base of the windshield.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,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM directs
battery current to the washer pump/motor unit. This
will cause the washer pump/motor unit to be ener-
gized for as long as the Wash switch is held closed up
to about thirty seconds, and to de-energize when the
front Wash switch is released.
When the control knob is depressed to the momen-
tary Wash position while the wiper system is operat-
ing in one of the Delay interval positions, the washer
pump/motor operation is the same. However, the
FCM also energizes the wiper on/off relay to override
the selected delay interval and operate the wiper
motor in a continuous low speed mode for as long as
the control knob is held depressed, then de-energizes
the relay and reverts to the selected delay mode
interval several wipe cycles after the control knob is
released. If the control knob is held depressed for
more than about thirty seconds, the FCM will sus-
pend washer pump/motor operation until the knob is
released for about two seconds, then cycled back to
the Wash position.
WIPE-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
while the wiper system is not operating, the instru-
ment cluster sends an electronic washer switch mes-
sage to the FCM, then the FCM the directs battery
current to the washer pump/motor unit and energizes
the wiper on/off relay. This will cause the washer
pump/motor unit to be energized and operate the
wiper motor in a continuous low speed mode for as
long as the Wash switch is held closed up to about
thirty seconds. When the control knob is released,
the FCM de-energizes the washer pump/motor unit,
but allows the wiper motor to operate for several
additional wipe cycles before it de-energizes the
wiper on/off relay and parks the wiper blades near
the base of the windshield.
If the control knob is held depressed for more than
about thirty seconds, the FCM will suspend washer
pump/motor operation until the knob is released for
about two seconds, then cycled back to the Wash
position; however, the wipers will continue to operate
for as long as the Wash switch is held closed. The
FCM monitors the changing state of the wiper motor
park switch through a hard wired wiper park switch
sense circuit input. This input allows the FCM to
count the number of wipe cycles that occur after the
Wash switch is released, and to determine the proper
DRWIPERS/WASHERS 8R - 5
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)

INSPECTION - WIPER & WASHER SYSTEM
WIPER SYSTEM
The wiper blades and wiper arms should be
inspected periodically, not just when wiper perfor-
mance problems are experienced. This inspection
should include the following points:
(1) Inspect the wiper arms for any indications of
damage, or contamination. If the wiper arms are con-
taminated with any foreign material, clean them as
required. (Refer to 8 - ELECTRICAL/WIPERS/
WASHERS - CLEANING). If a wiper arm is damaged
or corrosion is evident, replace the wiper arm with a
new unit. Do not attempt to repair a wiper arm that
is damaged or corroded.
(2) Carefully lift the wiper blade off of the glass.
Note the action of the wiper arm hinge. The wiper
arm should pivot freely at the hinge, but with no lat-
eral looseness evident. If there is any binding evident
in the wiper arm hinge, or there is evident lateral
play in the wiper arm hinge, replace the wiper arm.
CAUTION: Do not allow the wiper arm to spring
back against the glass without the wiper blade in
place or the glass may be damaged.
(3) Once proper hinge action of the wiper arm is
confirmed, check the hinge for proper spring tension.
Remove the wiper blade from the wiper arm. Either
place a small postal scale between the blade end of
the wiper arm and the glass, or carefully lift the
blade end of the arm away from the glass using a
small fish scale. Compare the scale readings between
the right and left wiper arms. Replace a wiper arm if
it has comparatively lower spring tension, as evi-
denced by a lower scale reading.
(4) Inspect the wiper blades and squeegees for any
indications of damage, contamination, or rubber dete-
rioration (Fig. 2). If the wiper blades or squeegees
are contaminated with any foreign material, clean
them and the glass as required. (Refer to 8 - ELEC-
TRICAL/WIPERS/WASHERS - CLEANING). After
cleaning the wiper blade and the glass, if the wiper
blade still fails to clear the glass without smearing,
streaking, chattering, hazing, or beading, replace the
wiper blade. Also, if a wiper blade is damaged or the
squeegee rubber is damaged or deteriorated, replace
the wiper blade with a new unit. Do not attempt to
repair a wiper blade that is damaged.
WASHER SYSTEM
The washer system components should be
inspected periodically, not just when washer perfor-
mance problems are experienced. This inspection
should include the following points:(1) Check for ice or other foreign material in the
washer reservoir. If contaminated, clean and flush
the washer system. (Refer to 8 - ELECTRICAL/WIP-
ERS/WASHERS - CLEANING).
(2) Inspect the washer plumbing for pinched, leak-
ing, deteriorated, or incorrectly routed hoses and
damaged or disconnected hose fittings. Replace dam-
aged or deteriorated hoses and hose fittings. Leaking
washer hoses can sometimes be repaired by cutting
the hose at the leak and splicing it back together
using an in-line connector fitting. Similarly, sections
of deteriorated hose can be cut out and replaced by
splicing in new sections of hose using in-line connec-
tor fittings. Whenever routing a washer hose or a
wire harness containing a washer hose, it must be
routed away from hot, sharp, or moving parts. Also,
sharp bends that might pinch the washer hose must
be avoided.CHECK VALVE
DESCRIPTION
A single washer system check valve is standard
equipment on this model, and is installed in the
Fig. 2 Wiper Blade Inspection
1 - WORN OR UNEVEN EDGES
2 - ROAD FILM OR FOREIGN MATERIAL DEPOSITS
3 - HARD, BRITTLE, OR CRACKED
4 - DEFORMED OR FATIGUED
5 - SPLIT
6 - DAMAGED SUPPORT COMPONENTS
DRWIPERS/WASHERS 8R - 7
WIPERS/WASHERS (Continued)

washer system plumbing (Fig. 3). The check valve is
integral to the washer nozzle plumbing wye fitting
located in the cowl plenum area beneath the cowl
plenum cover/grille panel near the base of the wind-
shield. The check valve consists of a molded plastic
body with a raised arrowhead molded into its center
section that indicates the direction of the flow
through the valve, and three barbed hose nipples
formed in a wye configuration on the outside circum-
ference of the center section of the valve body. The
check valve cannot be adjusted or repaired and, if
faulty or damaged, it must be replaced.
OPERATION
The check valve provides more than one function
in this application. It serves as a wye connector fit-
ting between the engine compartment and washer
nozzle sections of the washer supply hose. It prevents
washer fluid from draining out of the washer supply
hoses back to the washer reservoir. This drain-back
would result in a lengthy delay from when the
washer switch is actuated until washer fluid was dis-
pensed through the washer nozzles, because the
washer pump would have to refill the washer plumb-
ing from the reservoir to the nozzles. Such a drain-
back condition could also result in water, dirt, or
other outside contaminants being siphoned into the
washer system through the washer nozzle orifice.
This water could subsequently freeze and plug the
nozzle, while other contaminants could interfere with
proper nozzle operation and cause improper nozzle
spray patterns. In addition, the check valve prevents
washer fluid from siphoning through the washer noz-
zles after the washer system is turned Off.When the washer pump pressurizes and pumps
washer fluid from the reservoir through the washer
plumbing, the fluid pressure unseats a diaphragm
from over a sump well within the valve by overriding
the spring pressure applied to it by a piston (Fig. 4).
With the diaphragm unseated, washer fluid is
allowed to flow toward the two washer nozzles. When
the washer pump stops operating, the spring pres-
sure on the piston seats the diaphragm over the
sump well in the valve and fluid flow in either direc-
tion within the washer plumbing is prevented. The
check valve cannot be adjusted or repaired and, if
faulty or damaged, it must be replaced.REMOVAL
(1) Remove both wiper arms from the wiper pivots.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - REMOVAL).
(2) Unlatch and open the hood.
(3) Remove the cowl plenum cover/grille panel
from over the cowl plenum. (Refer to 23 - BODY/EX-
TERIOR/COWL GRILLE - REMOVAL).
(4) From the underside of the cowl plenum cover/
grille panel, disconnect the cowl plenum and washer
nozzle hoses from the three barbed nipples of the
check valve (Fig. 5).
(5) Remove the check valve from the underside of
the cowl plenum cover/grille panel.
INSTALLATION
(1) Position the check valve to the underside of the
cowl plenum cover/grille panel (Fig. 5). Be certain
that the flow direction arrow molded into the check
valve body is oriented towards the washer nozzles.
Fig. 3 Check Valve
1 - INLET NIPPLE
2 - CHECK VALVE
3 - OUTLET NIPPLE (2)
4 - FLOW DIRECTION ARROW
Fig. 4 Check Valve
1 - SPRING
2 - PISTON
3 - DIAPHRAGM
4 - TO WASHER NOZZLE
5 - FROM WASHER PUMP
8R - 8 WIPERS/WASHERSDR
CHECK VALVE (Continued)

(2) From the underside of the cowl plenum cover/
grille panel, reconnect the cowl plenum and washer
nozzle hoses to the three barbed nipples of the check
valve.
(3) Reinstall the cowl plenum cover/grille panel
over the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(4) Close and latch the hood.
(5) Reinstall both wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - INSTALLATION).
WASHER FLUID LEVEL
SWITCH
DESCRIPTION
The washer fluid level switch is a single pole, sin-
gle throw reed-type switch mounted on the outboard
side of the of the washer reservoir in the engine com-
partment (Fig. 6). Only the molded plastic switch
mounting flange and the integral connector recepta-
cle are visible when the switch is installed in the res-
ervoir. A short nipple formation extends from the
inner surface of the switch mounting flange, and a
barb on the nipple near the switch mounting flange
is pressed through a rubber grommet seal installed
in the mounting hole of the reservoir.
A small, molded plastic float has two pivot pins
near its center that are snapped into two receptacles
near the ends of two stanchions that extend toward
the float from the switch nipple formation. A small
magnet is secured within the end of the float nearestthe switch nipple formation, and a reed switch is con-
cealed within the nipple. A diagnostic resistor is con-
nected between the two switch terminals within the
switch mounting flange. The washer fluid level
switch cannot be adjusted or repaired. If faulty or
damaged, the switch must be replaced.
OPERATION
The washer fluid level switch uses a pivoting,
oblong float to monitor the level of the washer fluid
in the washer reservoir. The float contains a small
magnet. When the float pivots, the proximity of this
magnet to a stationary reed switch within the nipple
formation of the switch changes. When the fluid level
in the washer reservoir is at or above the float level,
the float moves to a vertical position, the influence of
the float magnetic field is removed from the reed
switch, and the normally open reed switch contacts
open. When the fluid level in the washer reservoir
falls below the level of the pivoting float, the float
moves to a horizontal position, the influence of the
float magnetic field is applied to the reed switch, and
the contacts of the normally open reed switch close.
The washer fluid level switch is connected to the
vehicle electrical system through a dedicated take
out and connector of the right (except diesel engines)
or left (diesel engines only) headlamp and dash wire
harness. The switch is connected in series between a
clean ground output of the Front Control Module
Fig. 5 Check Valve Remove/Install
1 - WASHER NOZZLE HOSE (RIGHT)
2 - CHECK VALVE
3 - ROUTING CLIP
4 - COWL PLENUM WASHER HOSE
5 - COWL PLENUM COVER/GRILLE PANEL (UNDERSIDE)
6 - WASHER NOZZLE HOSE (LEFT)
Fig. 6 Washer Fluid Level Switch
1 - MOUNTING FLANGE
2 - BARBED NIPPLE
3 - FLOAT
4 - RESERVOIR
5 - GROMMET SEAL
6 - PIVOT
7 - MAGNET
8 - CONNECTOR RECEPTACLE
DRWIPERS/WASHERS 8R - 9
CHECK VALVE (Continued)

INSTALLATION
(1) Install a new rubber grommet seal into the
washer fluid level switch mounting hole in the
washer reservoir. Always use a new rubber grommet
seal on the reservoir.
(2) Insert the float of the washer fluid level switch
through the rubber grommet seal and into the
washer reservoir. The connector receptacle of the
washer fluid level switch should be pointed upward.
(3) Using hand pressure, press firmly and evenly
on the washer fluid level switch mounting flange
until the barbed nipple is fully seated in the rubber
grommet seal in the washer reservoir mounting hole.
(4) Reconnect the right (except diesel engine) or
left (diesel engine only) headlamp and dash wire har-
ness connector for the washer fluid level switch to
the switch connector receptacle (Fig. 7) or (Fig. 8).
(5) Reconnect the removed washer hose to the
barbed outlet nipple of the washer pump/motor unit.
(6) Refill the washer reservoir with the washer
fluid drained from the reservoir during the removal
procedure.
(7) Reconnect the battery negative cable.
(8) Close and latch the hood.
WASHER HOSES/TUBES
DESCRIPTION
The washer plumbing consists of a small diameter
rubber reservoir washer hose that is routed from the
barbed outlet nipple of the electric washer pump/mo-tor unit on the washer reservoir through a trough
molded into the back of the reservoir above the
washer pump and to the engine compartment washer
hose (Fig. 9). On models equipped with an optional
diesel engine, the reservoir washer hose is routed
through routing clips on the top of the radiator fan
shroud from the washer reservoir on the left side of
the radiator to the engine compartment washer hose
on the right side of the radiator. The engine compart-
ment washer hose is contained within the right head-
lamp and dash wire harness, which is routed through
the engine compartment along the top of the right
front fender wheel house to the dash panel.
The engine compartment washer hose is connected
to the washer reservoir washer hose and to the cowl
plenum washer hose with molded plastic in-line fit-
tings that have a barbed nipple on each end. The
cowl plenum washer hose is routed from the engine
compartment into the cowl plenum area through a
trough formation located near the right end of the
cowl plenum cover/grille panel. The cowl plenum
washer hose is connected to the washer system check
valve/wye fitting on the underside of the cowl plenum
cover/grille panel. The cowl plenum washer hose and
the two washer nozzle hoses are routed through inte-
gral routing clips on the underside of the cowl ple-
num cover/grille panel. The cowl plenum washer hose
is connected to one nipple on the wye fitting and the
two washer nozzle hoses are connected to the other
two wye fitting nipples. The washer nozzle hoses are
then routed along the underside of the cowl plenum
cover/grille panel to the two washer nozzles.
Washer hose is available for service only as roll
stock, which must then be cut to length. 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 washer pump/motor through the
washer system plumbing and fittings to the two
washer nozzles. 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.
WASHER NOZZLE
DESCRIPTION
The two washer nozzles have integral snap fea-
tures and an anti-rotation tab that secure them in
dedicated holes in the cowl plenum cover/grille panel
located near the base of the windshield (Fig. 10). The
Fig. 9 Engine Compartment Washer Hose
1 - RIGHT FENDER
2 - RIGHT HEADLAMP & DASH WIRE HARNESS
3 - ENGINE COMPARTMENT WASHER HOSE (TO COWL
PLENUM)
4 - COWL PLENUM WASHER HOSE
5 - ENGINE COMPARTMENT WASHER HOSE (TO WASHER
RESERVOIR)
DRWIPERS/WASHERS 8R - 11
WASHER FLUID LEVEL SWITCH (Continued)

(7) Reinstall both wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - INSTALLATION).
WASHER PUMP/MOTOR
DESCRIPTION
The washer pump/motor unit (Fig. 12) is located on
the rearward facing surface of the washer reservoir,
in the right (except diesel engine) or left (diesel
engine only) front corner of the engine compartment.
A small permanently lubricated and sealed electric
motor is coupled to the rotor-type washer pump. A
seal flange with a barbed inlet nipple on the pump
housing passes through a rubber grommet seal
installed in a dedicated mounting hole of the washer
reservoir. When the pump is installed in the reser-
voir a barbed outlet nipple on the pump housing con-
nects the unit to the washer system through a short
washer reservoir hose.
The washer pump/motor unit is retained on the
reservoir by the interference fit between the barbed
pump inlet nipple and the grommet seal, which is a
light press fit. The top of the washer pump is also
secured to the washer reservoir by the use of a snappost on the motor housing and a snap post receptacle
molded into the reservoir that allows for mounting of
the washer pump without the use of fasteners. An
integral connector receptacle on the top of the motor
housing connects the unit to the vehicle electrical
system. The washer pump/motor unit cannot be
repaired. If faulty or damaged, the entire washer
pump/motor unit must be replaced.
OPERATION
The washer pump/motor unit features a small
Direct Current (DC) electric motor. The motor is con-
nected to the vehicle electrical system through a sin-
gle take out and two-cavity connector of the right
(except diesel engine) or left (diesel engine only)
headlamp and dash wire harness. The motor is
grounded at all times through another take out of
the right (except diesel engine) or left (diesel engine
only) headlamp and dash wire harness. On models
without the diesel engine, a single eyelet terminal
connector is secured by a nut to a ground stud
located on the right front fender inner shield in the
engine compartment. On models with a diesel engine,
an eyelet terminal connector is secured by a ground
screw to the left front fender inner shield in the
engine compartment. The motor receives battery cur-
rent on a washer pump/motor control circuit.
The washer pump/motor control circuit is energized
through a high side driver within the Front Control
Module (FCM) whenever the FCM receives an elec-
tronic message requesting washer system operation
from the instrument cluster over the Programmable
Communications Interface (PCI) data bus. The
instrument cluster monitors a resistor multiplexed
hard wired input from the momentary washer switch
contacts within the multi-function switch on the
steering column to determine when it should issue
the electronic message requesting washer system
operation.
Washer fluid is gravity-fed from the washer reser-
voir to the inlet side of the washer pump. When the
pump motor is energized, the motor spins the rotor
within the washer pump. The spinning pump rotor
pressurizes the washer fluid and forces it through
the pump outlet nipple, the washer plumbing, and
the washer nozzles onto the windshield glass.
The washer pump/motor unit may be diagnosed
using conventional diagnostic tools and methods.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the instrument
cluster, the FCM, or the electronic message inputs to
or outputs from the instrument cluster and the FCM
that control the operation of the washer pump/motor
unit. The most reliable, efficient, and accurate means
to diagnose the washer pump/motor unit, the instru-
ment cluster, the FCM, or the electronic message
Fig. 12 Washer Pump/Motor
1 - MOTOR
2 - SNAP POST
3 - CONNECTOR RECEPTACLE
4 - PUMP
5 - OUTLET NIPPLE
6 - INLET NIPPLE
7 - FILTER SCREEN
DRWIPERS/WASHERS 8R - 13
WASHER NOZZLE (Continued)