2006 MERCEDES-BENZ SPRINTER relay

both the wiper and washer systems. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
MULTI-FUNCTION SWITCH - DESCRIPTION)
²Rain Sensor- Vehicles equipped with an
optional automatic wiper feature have an electronic
rain sensor concealed within the base of the rear
view mirror unit on the inside of the laminated wind-
shield glass.
²Rain Sensor Control Module- Vehicles
equipped with an optional automatic wiper feature
have an electronic rain sensor control module located
under the lower instrument panel above the acceler-
ator pedal in the passenger compartment of the vehi-
cle.
²Washer Fluid Level Switch- The optional
washer fluid level switch is integral to a unique ver-
sion of the washer pump/motor unit, which is located
in a dedicated hole on the top of the sump area near
the back of the windshield washer reservoir on the
right front fender wheel house in the engine com-
partment.
²Washer Nozzle- A single washer nozzle with
three separate orifices is secured with integral snap
features to each wiper arm. The hoses for the washer
nozzles are concealed beneath a molded plastic guide
on the underside of each wiper arm and routed to the
engine compartment through unique molded plastic
elbow fittings located near each wiper pivot at the
base of the windshield.
²Washer Pump/Motor- Two different washer
pump/motor units are available for this model. One
version has an integral washer fluid level switch that
provides a hard wired input to the instrument cluster
for control of the optional washer fluid indicator. The
washer pump/motor unit is located in a dedicated
hole on the top of the sump area near the back of the
windshield washer reservoir on the right front fender
wheel house in the engine compartment.
²Washer Reservoir- The washer reservoir is
located on the right front fender wheel house in the
engine compartment. The washer reservoir filler is
accessed from the right front corner of the engine
compartment.
²Wiper Arm- The two unequal length wiper
arms are secured to the two wiper pivots, which
extend through the cowl panel near the base of the
windshield. The longer arm is installed on the left
(driver) side of the windshield.
²Wiper Blade- The two unequal length wiper
blades are secured to the two wiper arms, and are
parked on the glass near the bottom of the wind-
shield when the wiper system is not in operation.
The longer blade is installed on the left (driver) side
of the windshield.
²Wiper Linkage- The wiper pivots are the only
visible components of the wiper linkage. The remain-
der of the linkage is concealed within the engine
compartment just behind the hood opening. Thewiper linkage module includes the two wiper drive
links, the wiper motor crank arm, the two wiper piv-
ots, and the linkage and motor mounting bracket.
²Wiper Motor- The wiper motor is secured to
the wiper linkage module bracket on the underside of
the cowl panel within the engine compartment. The
wiper motor output shaft and crank arm extend
through a clearance hole in the mounting bracket,
where they are connected to a crank arm that drives
the wiper linkage.
²Wiper Relay- The wiper relay is located in a
dedicated receptacle on the lower left surface of the
fuse block underneath the steering column behind
the fuse access panel and the steering column open-
ing panel. The wiper relay is a passive component on
vehicles equipped with the optional automatic wiper
system.
²Wiper, Turn Signals, Engine Start Control
Module- The wiper, turn signals and engine start
control module is integral to the fuse block located
underneath the steering column. The fuse block is
concealed behind the fuse access panel and the steer-
ing column opening panel, where it is secured with
screws to the steering column. The wiper system
functions of this module are passive on vehicles
equipped with the optional automatic wiper system.
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.
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
VAWIPERS/WASHERS 8R - 3

other minor debris from the outside windshield glass
surface that might be encountered while driving the
vehicle under numerous types of inclement operating
conditions.
Two wiper systems are available: the standard
intermittent wipe system, or an optional automatic
wipe system. The vehicle operator initiates all wiper
and washer system functions with the multi-function
switch wiper control stalk that extends from the
right side of the steering column, just below the
steering wheel. Depressing, raising, or pulling the
right control stalk of the multi-function switch
selects the desired wiper system operating mode (Fig.
2). The wiper system allows the vehicle operator to
select from two continuous wiper speeds, Hi or Lo,
either a fixed interval intermittent wipe mode or an
auto wipe mode (as the vehicle is equipped), and a
pulse wipe mode. Pushing the knob on the end of the
control stalk towards the steering column activates
the washer pump/motor, which dispenses washer
fluid onto the windshield glass through the washer
nozzles.
The hard wired inputs to and outputs from the
wiper and washer system components may be diag-
nosed and tested using conventional diagnostic tools
and methods. Refer to the appropriate diagnostic
information. Refer to the owner's manual in the vehi-
cle glove box for more information on the features
and operation of the wiper and washer system.
INTERMITTENT WIPE SYSTEM
When the ignition switch is in the On position, bat-
tery current from a fuse in the fuse block underneath
the steering column is provided through a fused igni-
tion switch output (run-start) circuit to the intermit-tent wipe logic circuitry of the wiper, turn signals
and engine start control module within the fuse
block, the multi-function switch, the wiper relay and
the wiper motor park switch. The internal circuitry
of the multi-function switch provides a direct hard
wired battery current output to the low speed or high
speed brushes of the wiper motor when the Low,
High, or Pulse position is selected, which causes the
wipers to cycle at the selected speed for as long as
that switch position remains selected.
In order to provide the intermittent wipe and wipe-
after-wash features, the intermittent wipe logic cir-
cuitry of the wiper, turn signals and engine start
control module within the fuse block monitors inputs
from the intermittent wipe and washer switch cir-
cuitry of the multi-function switch and the park
switch in the wiper motor. When the intermittent
wipe position is selected with the multi-function
switch control stalk, the intermittent wipe logic cir-
cuitry responds by energizing the wiper relay and
calculating the correct delay interval. The energized
wiper relay directs battery current through the inter-
mittent wipe position circuitry of the multi-function
switch to the low speed brush of the wiper motor.
The intermittent wipe logic circuit monitors the
wiper motor operation through the wiper on/off relay
output circuit, which allows it to determine the
proper timing to begin the next wiper blade sweep.
The normal delay interval is about five seconds.
When the Off position of the multi-function switch
wiper control stalk is selected, one of two events is
possible. The event that will occur depends upon the
position of the wiper blades on the windshield at the
moment that the 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, the intermittent wipe logic circuit de-ener-
gizes the wiper 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 closed to battery current
through the fused ignition switch output (run-start)
circuit. The intermittent wipe logic circuit energizes
the wiper relay and the wiper on-off relay output cir-
cuit directs battery current to the low speed brush of
the wiper motor through the normally open contact
of the wiper relay, then through the internal Off posi-
tion circuitry of the multi-function switch. This
causes the wiper motor to continue running until the
wiper blades are in the down position on the wind-
shield and the park switch is again closed to ground.
When the Wash position of the control knob on the
right control stalk of the multi-function switch is
selected, the washer switch circuitry directs battery
current to the washer pump motor and to the inter-
mittent wipe logic circuitry. When the washer switch
Fig. 2 Windshield Wiper/Washer Switch
1 - INTERMITTENT WIPE MODE (OR AUTO WIPE MODE IF
EQUIPPED)
2 - CONTINUOUS LOW SPEED WIPE MODE
3 - CONTINUOUS HIGH SPEED WIPE MODE
4 - WASHER MODE
5 - PULSE WIPE MODE
8R - 4 WIPERS/WASHERSVA

is closed with the wiper system turned Off, the inter-
mittent wipe logic circuitry operates the wiper motor
in the same manner as it does to provide the inter-
mittent wipe mode operation. After the state of the
washer switch changes to open, the intermittent wipe
logic circuitry monitors the wiper motor through the
wiper on-off relay output circuit, which allows it to
monitor the number of wiper blade sweeps. After the
appropriate number of wiper sweeps the intermittent
wipe logic circuitry operates the wiper motor to
return the wipers to their park position, then de-en-
ergizes the wiper relay.
AUTOMATIC WIPE SYSTEM
When the ignition switch is in the On position, bat-
tery current from a fuse in the fuse block underneath
the steering column is provided through a fused igni-
tion switch output (run-start) circuit to the rain sen-
sor control module under the instrument panel, to
the rain sensor within the base of the inside rear
view mirror on the windshield, and to the multi-func-
tion switch. The internal circuitry of the multi-func-
tion switch provides direct hard wired battery
current outputs to the rain sensor control module to
indicate the selected wiper operating mode. The con-
trol module logic monitors the inputs from the multi-
function switch as well as from the rain sensor and
the wiper motor park switch in order to provide the
outputs necessary to operate the wiper motor and the
washer pump motor as requested.
When the automatic wipe position is selected with
the multi-function switch control stalk, the rain sen-
sor control module logic circuitry responds by provid-
ing an acknowledgment sweep of the wipers. The
rain sensor calculates the correct wiper speed and
wiper sweep intervals required to remove the mois-
ture detected on the windshield glass and provides
this input to the rain sensor control module. The con-
trol module then energizes and de-energizes the
wiper motor automatically. The automatic wipe logic
will also provide a wipe-after-wash feature to clear
washer fluid that is directed onto the windshield
when the washer system is utilized.
When the Off position of the multi-function switch
wiper control stalk is selected, one of two events is
possible. The event that will occur depends upon the
position of the wiper blades on the windshield at the
moment that the 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 the rain sensor control module logic cir-
cuit de-energizes the wiper motor. If the wiper blades
are not in the down position at the moment the Off
position is selected, the park switch is an open cir-
cuit. The control module logic circuit directs battery
current to the low speed brush of the wiper motor,
which causes the wiper motor to continue runninguntil the wiper blades are in the down position on
the windshield and the park switch is again closed to
ground.
When the Wash position of the control knob on the
right control stalk of the multi-function switch is
selected with the wiper system turned Off, the rain
sensor control module logic circuitry operates the
wiper motor in the same manner as it does to provide
the automatic wipe mode operation. After the state of
the washer switch changes to open the control mod-
ule monitors the wiper motor through the wiper park
switch sense circuit, which allows it to monitor the
number of wiper blade sweeps. After the appropriate
number of wiper sweeps the control module operates
the wiper motor to return the wipers to their park
position, then de-energizes the wiper motor.
OPERATING MODES
The components of the wiper and washer system
are designed to provide the following operating
modes:
²Automatic Wipe Mode- On vehicles so
equipped, the internal circuitry of the multi-function
switch, the rain sensor control module and the rain
sensor work in concert to provide wiper system oper-
ation automatically whenever moisture is detected on
the windshield glass.
²Continuous Wipe Mode- The two-speed wiper
motor, the internal circuitry of the multi-function
switch, and the wiper system logic circuits work in
concert to provide two continuous wipe cycles, low
speed or high speed.
²Intermittent Wipe Mode- On vehicles so
equipped, the internal circuitry of the multi-function
switch, the intermittent wipe circuitry of the wiper,
turn signals and engine start control module in the
fuse block, and the wiper relay work in concert to
provide an intermittent wipe mode with a single,
fixed delay interval.
²Pulse Wipe Mode- The internal circuitry of
the multi-function switch and the wiper system logic
circuits work in concert to provide a pulse wipe mode
that will allow the wiper motor to be operated for a
single, complete wipe cycle.
²Washer Mode- When the washer system is
activated with the multi-function switch while the
wiper system is operating, washer fluid will be dis-
pensed onto the windshield glass through the washer
nozzles for as long as the washer pump/motor is
energized.
²Wipe-After-Wash Mode- The wiper system
logic circuitry provides a wipe-after-wash feature. If
the wipers are turned Off, this feature will operate
the washer pump/motor and the wipers for as long as
the washer system is activated, then provide several
additional wipe cycles after the washer system is
deactivated before parking the wiper blades near the
base of the windshield.
VAWIPERS/WASHERS 8R - 5

DIAGNOSIS AND TESTING - WIPER &
WASHER SYSTEM
If the wiper motor operates, but the wipers do not
move on the windshield, replace the faulty wiper
linkage module. If the washer pump/motor operates,
but no washer fluid is dispensed on the glass; or, if
the wipers operate, but chatter, lift, or do not clear
the glass, clean and inspect the wiper and washer
system components as required. (Refer to 8 - ELEC-
TRICAL/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/LIGHTING - EXTERIOR/MULTI-FUNC-
TION SWITCH - 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.
The hard wired circuits and components of the
wiper and washer system may be diagnosed andtested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
intermittent wipe logic circuitry contained within the
fuse block underneath the steering column, the rain
sensor within the base of the rear view mirror on the
windshield, or the rain sensor control module under
the instrument panel.
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
INTERMITTENT WIPER SYSTEM
CONDITION POSSIBLE CAUSES CORRECTION
WIPERS INOPERATIVE IN
ALL SWITCH POSITIONS1. Faulty or missing fuse. 1. Test and replace the fuse as required.
2. Faulty wiper motor ground circuit. 2. Test and repair the open ground circuit
as required.
3. Faulty multi-function switch feed
circuit.3. Test and repair the open fused ignition
switch output circuit between the fuse and
the multi-function switch as required.
4. Faulty multi-function switch. 4. Test and replace the multi-function
switch as required.
5. Faulty wiper motor. 5. Test and replace the wiper motor as
required.
WIPERS INOPERATIVE IN
INTERMITTENT POSITION
AND NO WIPE AFTER
WASH FEATURE1. Faulty wiper relay. 1. Test and replace the wiper relay as re-
quired.
2. Faulty multi-function switch. 2. Test and replace the multi-function
switch as required.
3. Faulty intermittent wipe logic cir-
cuit.3. Replace the steering column fuse block
as required.
WIPERS INOPERATIVE IN
LOW POSITION AND NO
PULSE FEATURE1. Faulty low speed circuit. 1. Test and repair the open low speed cir-
cuit between the multi-function switch and
the wiper motor as required.
2. Faulty multi-function switch. 2. Test and replace the multi-function
switch as required.
3. Faulty wiper low speed brush. 3. Test and replace the wiper motor as
required.
8R - 6 WIPERS/WASHERSVA

CONDITION POSSIBLE CAUSES CORRECTION
WIPERS INOPERATIVE IN
HIGH POSITION1. Faulty high speed circuit. 1. Test and repair the open high speed
circuit between the multi-function switch
and the wiper motor as required.
2. Faulty multi-function switch. 2. Test and replace the multi-function
switch as required.
3. Faulty wiper high speed brush. 3. Test and replace the wiper motor as
required.
WIPERS DO NOT PARK
AFTER OPERATING1. Faulty motor feed circuit. 1. Test and repair the open fused ignition
switch output circuit to the wiper motor as
required.
2. Faulty park switch output circuit. 2. Test and repair the open or shorted cir-
cuit between the wiper park switch and
the wiper relay as required.
3. Faulty wiper relay. 3. Test and replace the wiper relay as re-
quired.
4. Faulty park switch. 4. Test and replace the wiper motor as
required.
WASHERS INOPERATIVE 1. Faulty washer pump ground cir-
cuit.1. Test and repair the open ground circuit
as required.
2. Faulty washer pump feed circuit. 2. Test and repair the open circuit be-
tween the multi-function switch and the
washer pump as required.
3. Faulty washer pump motor. 3. Test and replace the washer pump as
required.
4. Faulty muli-function switch. 4. Test and replace the multi-function
switch as required.
AUTOMATIC WIPER SYSTEM
CONDITION POSSIBLE CAUSES CORRECTION
WIPERS INOPERATIVE IN
ALL SWITCH POSITIONS1. Faulty or missing fuse. 1. Test and replace the fuse as required.
2. Faulty wiper motor ground circuit. 2. Test and repair the open ground circuit
as required.
3. Faulty wiper motor. 3. Test and replace the wiper motor as
required.
4. Faulty multi-function switch feed
circuit.4. Test and repair the open fused ignition
switch output circuit between the fuse and
the multi-function switch as required.
5. Faulty multi-function switch. 5. Test and replace the multi-function
switch as required.
6. Faulty rain sensor control module
ground circuit.6. Test and repair the open ground circuit
as required.
7. Faulty rain sensor control module
feed circuit.7. Test and repair the open fused ignition
switch output circuit between the fuse and
the rain sensor control module as re-
quired.
8. Faulty rain sensor control mod-
ule.8. Test and replace the rain sensor control
module as required.
VAWIPERS/WASHERS 8R - 7

CONDITION POSSIBLE CAUSES CORRECTION
WIPERS DO NOT PARK
AFTER OPERATING1. Faulty park switch output circuit. 1. Test and repair the open or shorted cir-
cuit between the wiper park switch and
the rain sensor control module as re-
quired.
2. Faulty wiper relay output circuit. 2. Test and repair the open or shorted cir-
cuit between the rain sensor control mod-
ule and the wiper relay as required.
3. Faulty wiper relay. 3. Test and replace the wiper relay as re-
quired.
4. Faulty park switch. 4. Test and replace the wiper motor as
required.
5. Faulty intermittent wipe logic cir-
cuit.5. Replace the steering column fuse block
as required.
WASHERS INOPERATIVE 1. Faulty washer pump ground cir-
cuit.1. Test and repair the open ground circuit
as required.
2. Faulty washer pump request cir-
cuit.2. Test and repair the open washer pump
request circuit between the multi-function
switch and the rain sensor control module
as required.
3. Faulty muli-function switch. 3. Test and replace the multi-function
switch as required.
4. Faulty washer pump control cir-
cuit.4. Test and repair the open washer pump
control circuit between the rain sensor
control module and the washer pump as
required.
5. Faulty washer pump motor. 5. Test and replace the washer pump as
required.
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 nipple and the washer reservoir using clean
washer fluid, a mild detergent, or a non-abrasive
cleaner. Flush foreign material from the washer sys-
tem 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.
VAWIPERS/WASHERS 8R - 9

OPERATION
The wiper motor operation is controlled by the
vehicle operator through battery current inputs
received by the wiper motor from the wiper switch
circuitry of the multi-function switch on the top of
the steering column, and from the wiper relay on the
fuse block underneath the steering column. The
wiper motor speed is controlled by current flow to
either the low speed or the high speed set of brushes.
The automatic resetting circuit breaker protects the
motor from overloads.
The park switch consists of a contact disc and
three contacts. The contact disc is mechanically fas-
tened to and rotated with a gear in the wiper motor
transmission. Two input contacts alternately close
the wiper park switch sense output circuit contact to
ground or to battery current, depending upon the
position of the wipers on the glass. This feature
allows the intermittent wipe logic circuit to monitor
the position and the cycles of the wiper motor to pro-
vide the intermittent wipe and wipe-after-wash
modes, as well as allowing the motor to complete its
current wipe cycle after the wiper system has been
turned Off and park the wiper blades in the lowest
portion of the wipe pattern.
The wiper motor may be diagnosed using conven-
tional diagnostic tools and methods.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the vehicle wire harness connector
for the wiper motor from the motor pigtail wire con-
nector (Fig. 32).
8R - 32 WIPERS/WASHERSVA

WIPER RELAY
DESCRIPTION
A wiper relay is standard equipment on all models.
The wiper relay (or intermittent wipe relay) is
located in a dedicated receptacle on the bottom left of
the fuse block on the underside of the steering col-
umn (Fig. 33). The wiper relay is a conventional
International Standards Organization (ISO) micro
relay. Relays conforming to the ISO specifications
have common physical dimensions, current capaci-
ties, terminal patterns, and terminal functions. The
relay is contained within a small, rectangular,
molded plastic housing. The relay is connected to all
of the required inputs and outputs through the
instrument panel wire harness connector by five
male spade-type terminals that extend from the bot-
tom of the relay base. The ISO designation for each
terminal is molded into the base adjacent to the ter-
minal. The ISO terminal designations are as follows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
The wiper relay cannot be adjusted or repaired. If
the relay is damaged or faulty, it must be replaced.
OPERATION
The wiper relay (or intermittent wipe relay) is an
electromechanical switch that uses a low current
input from the intermittent wipe logic circuitry
within the fuse block underneath the steering column
to control a high current output to the low speed
brush of 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 or diode 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 relay terminals are connected to the
vehicle electrical system through a connector recepta-
cle in the fuse block. The inputs and outputs of the
wiper relay include:
²The common feed terminal (30) provides an out-
put to the wiper motor low speed brush through the
wiper control circuitry of the multi-function switch on
the steering column. When the wiper relay is de-en-
ergized, the common feed terminal is connected to
the input of the relay normally closed terminal (87).
When the wiper relay is energized, the common feed
terminal is connected to the input of the relay nor-
mally open terminal (87A).
²The coil ground terminal (85) is connected to
battery current through a fused ignition switch out-
put circuit whenever the ignition switch is in the On
position.
²The coil battery terminal (86) is connected to the
relay control output of the wiper, turn signals and
engine start control module within the fuse block
through the wiper relay control circuit. This elec-
tronic circuitry controls the ground path for this cir-
cuit internally to energize or de-energize the wiper
relay control coil based upon its programming and
inputs from the wiper and washer control circuitry of
the multi-function switch, the wiper motor park
switch, and the ignition switch.
²The normally open terminal (87) is connected to
the output of the wiper motor park switch through
the wiper motor park switch sense circuit. This cir-
cuit can carry either battery current (wipers are not
in park position) or ground (wipers are in park posi-
tion), depending upon the status of the wiper park
switch.
Fig. 33 Wiper Relay
1 - HOUSING
2 - TERMINAL (5)
3 - BASE
8R - 34 WIPERS/WASHERSVA