engine oil DODGE RAM 2002 Service Owners Manual

engine coolant temperature gauge is serviced as a
unit with the instrument cluster.
OPERATION
The engine coolant temperature gauge gives an
indication to the vehicle operator of the engine cool-
ant temperature. This gauge is controlled by the
instrument cluster circuit board based upon the clus-
ter programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Chrysler Collision Detection (CCD)
data bus. The engine coolant temperature gauge is
an air core magnetic unit that receives battery cur-
rent on the instrument cluster electronic circuit
board through the fused ignition switch output (st-
run) circuit whenever the ignition switch is in the On
or Start positions. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Temperature Message- Each time
the cluster receives a message from the PCM indicat-
ing the engine coolant temperature is between the
low end of normal [about 57É C (130É F) for gasoline
engines, or 60É C (140É F) for diesel engines] and the
high end of normal [about 129É C (264É F) for gaso-
line engines, or 116É C (240É F) for diesel engines],
the gauge needle is moved to the actual temperature
position on the gauge scale.
²Engine Temperature Low Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is below
the low end of normal [about 57É C (130É F) for gas-
oline engines, or 60É C (140É F) for diesel engines],
the gauge needle is held at the lowest increment [57É
C (130É F) for gasoline engines, or 60É C (140É F) for
diesel engines] at the far left end of the gauge scale.
The gauge needle remains at the far left end of the
scale until the cluster receives a message from the
PCM indicating that the engine temperature is above
about 57É C (130É F) for gasoline engines, or 60É C
(140É F) for diesel engines, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Engine Temperature High Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is above
about 122É C (253É F) for gasoline engines, or 112É C
(233É F) for diesel engines, the gauge needle is moved
to the appropriate position on the gauge scale, the
check gauges indicator is illuminated, and a single
chime tone is sounded. The check gauges indicator
remains illuminated until the cluster receives a mes-
sage from the PCM indicating that the engine tem-perature is below about 119É C (246É F) for gasoline
engines, or 109É C (226É F) for diesel engines, or
until the ignition switch is turned to the Off position,
whichever occurs first. The chime tone feature will
only repeat during the same ignition cycle if the
check gauges indicator is cycled off and then on
again by the appropriate engine temperature mes-
sages from the PCM.
²Message Failure- If the cluster fails to receive
an engine temperature message, it will hold the
gauge needle at the last indication until a new mes-
sage is received, or until the ignition switch is turned
to the Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the engine coolant
temperature sensor to determine the engine operat-
ing temperature. The PCM then sends the proper
engine coolant temperature messages to the instru-
ment cluster. For further diagnosis of the engine cool-
ant temperature gauge or the instrument cluster
circuitry that controls the gauge, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the check gauges indicator due to a high engine tem-
perature gauge reading, it may indicate that the
engine or the engine cooling system requires service.
For proper diagnosis of the engine coolant tempera-
ture sensor, the PCM, the CCD data bus, or the mes-
sage inputs to the instrument cluster that control the
engine coolant temperature gauge, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
FUEL GAUGE
DESCRIPTION
A fuel gauge is standard equipment on all instru-
ment clusters. The fuel gauge is located in the lower
right quadrant of the instrument cluster, below the
oil pressure gauge. The fuel gauge consists of a mov-
able gauge needle or pointer controlled by the instru-
ment cluster circuitry and a fixed 90 degree scale on
the cluster overlay that reads left-to-right from E (or
Empty) to F (or Full). An International Control and
Display Symbol icon for ªFuelº is located on the clus-
ter overlay, directly below the highest graduation of
the gauge scale. The text ªFUEL DOORº and an
arrowhead pointed to the left side of the vehicle is
imprinted on the cluster overlay directly below the
fuel gauge to provide the driver with a reminder as
BR/BEINSTRUMENT CLUSTER 8J - 19
ENGINE TEMPERATURE GAUGE (Continued)

played when the ignition switch was turned to the
Off position.
²Trip Odometer Reset- When the trip odome-
ter reset switch is pressed and held for longer than
about two seconds, the trip odometer will be reset to
000.0 kilometers (miles). The VFD must be display-
ing the trip odometer information in order for the
trip odometer information to be reset.
²Message Failure- If the cluster fails to receive
a distance message during normal operation, it will
flash the odometer/trip odometer distance informa-
tion on and off repeatedly until a distance message is
received, or until the ignition switch is turned to the
Off position, whichever occurs first. If the cluster
does not receive a distance message within one sec-
ond after the ignition switch is turned to the On posi-
tion, it will display the last distance message stored
in the cluster memory. If the cluster is unable to dis-
play distance information due to an error internal to
the cluster, the VFD display will be blank.
²Actuator Test- Each time the cluster is put
through the actuator test, the VFD will display all of
its characters at once, then step through each char-
acter segment individually during the VFD portion of
the test to confirm the functionality of the VFD and
the cluster control circuitry.
The PCM continually monitors the vehicle speed
sensor, then sends the proper distance messages to
the instrument cluster. For further diagnosis of the
odometer/trip odometer or the instrument cluster cir-
cuitry that controls these functions, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
vehicle speed sensor, the PCM, the CCD data bus, or
the message inputs to the instrument cluster that
control the odometer/trip odometer, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
OIL PRESSURE GAUGE
DESCRIPTION
An oil pressure gauge is standard equipment on all
instrument clusters. The oil pressure gauge is located
in the upper right quadrant of the instrument clus-
ter, above the fuel gauge. The oil pressure gauge con-
sists of a movable gauge needle or pointer controlled
by the instrument cluster circuitry and a fixed 90
degree scale on the cluster overlay that reads left-to-
right either from 0 kPa (0 psi) to 758 kPa (110 psi).
An International Control and Display Symbol icon for
ªEngine Oilº is located on the cluster overlay, directly
below the highest graduation of the gauge scale. The
oil pressure gauge graphics are white against a black
field except for a single red graduation at the lowend of the gauge scale, making them clearly visible
within the instrument cluster in daylight. When illu-
minated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-
rior lamps turned On, the white graphics appear
blue-green and the red graphics appear red. The
orange gauge needle is internally illuminated. Gauge
illumination is provided by replaceable incandescent
bulb and bulb holder units located on the instrument
cluster electronic circuit board. The oil pressure
gauge is serviced as a unit with the instrument clus-
ter.
OPERATION
The oil pressure gauge gives an indication to the
vehicle operator of the engine oil pressure. This
gauge is controlled by the instrument cluster circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Chrysler
Collision Detection (CCD) data bus. The oil pressure
gauge is an air core magnetic unit that receives bat-
tery current on the instrument cluster electronic cir-
cuit board through the fused ignition switch output
(st-run) circuit whenever the ignition switch is in the
On or Start positions. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Oil Pressure Message- The instru-
ment cluster circuitry restricts the oil pressure gauge
needle operation in order to provide readings that
are consistent with customer expectations. Each time
the cluster receives a message from the PCM indicat-
ing the engine oil pressure is between about 6.9 kPa
(1 psi) and 137.9 kPa (20 psi) for gasoline engines, or
55 kPa (8 psi) and 58.6 kPa (8.5 psi) for diesel
engines, the cluster holds the gauge needle at a point
about 11 degrees above the low end of normal incre-
ment on the gauge scale. Each time the cluster
receives a message from the PCM indicating the
engine oil pressure is between about 517.1 kPa (75
psi) and 755 kPa (109.5 psi) for gasoline engines, or
551.6 kPa (80 psi) and 755 kPa (109.5 psi) for diesel
engines, the cluster holds the gauge needle at a point
about 7.4 degrees below the high end of normal
increment on the gauge scale. When the cluster
receives messages from the PCM indicating the
engine oil pressure is between about 137.9 kPa (20
psi) and 517.1 kPa (75 psi) for gasoline engines, or
58.6 kPa (8.5 psi) and 551.6 kPa (80 psi) for diesel
engines], the gauge needle is moved to the actual
pressure position on the gauge scale.
BR/BEINSTRUMENT CLUSTER 8J - 25
ODOMETER (Continued)

²Engine Oil Pressure Low Message- Each
time the cluster receives a message from the PCM
indicating the engine oil pressure is below about 6.9
kPa (1 psi) for gasoline engines, or 55 kPa (8 psi) for
diesel engines, the gauge needle is moved to the 0
kPa (0 psi) graduation at the far left (low) end of the
gauge scale, the check gauges indicator is illumi-
nated, and a single chime tone is generated. The
gauge needle remains at the low end of the scale and
the check gauges indicator remains illuminated until
the cluster receives a message from the PCM indicat-
ing that the engine oil pressure is above about 6.9
kPa (1 psi) for gasoline engines, or 55 kPa (8 psi) for
diesel engines, or until the ignition switch is turned
to the Off position, whichever occurs first. The clus-
ter will only turn the check gauges indicator lamp on
in response to an engine oil pressure low message if
the engine speed message is greater than zero.
²Engine Oil Pressure High Message- Each
time the cluster receives a message from the PCM
indicating the engine oil pressure is above about 755
kPa (109.5 psi) for gasoline or diesel engines, the
gauge needle is moved to the 758.4 kPa (110 psi)
graduation at the far right (high) end of the gauge
scale. The gauge needle remains at the high end of
the scale until the cluster receives a message from
the PCM indicating that the engine oil pressure is
below about 755 kPa (109.5 psi) for gasoline or diesel
engines, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Message Failure- If the cluster fails to receive
an engine oil pressure message, it will hold the
gauge needle at the last indication until a new mes-
sage is received, or until the ignition switch is turned
to the Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the engine oil pres-
sure sensor to determine the engine oil pressure. The
PCM then sends the proper engine oil pressure mes-
sages to the instrument cluster. For further diagnosis
of the oil pressure gauge or the instrument cluster
circuitry that controls the gauge, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the check gauges indicator due to a low oil pressure
gauge reading, it may indicate that the engine or the
engine oiling system requires service. For proper
diagnosis of the engine oil pressure sensor, the PCM,
the CCD data bus, or the message inputs to the
instrument cluster that control the oil pressuregauge, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
OVERDRIVE OFF INDICATOR
DESCRIPTION
An overdrive off indicator is standard equipment
on all instrument clusters. However, on vehicles not
equipped with the optional overdrive automatic
transmission, this indicator is electronically disabled.
The overdrive off indicator is located near the lower
edge of the instrument cluster overlay, to the right of
center. The overdrive off indicator consists of a sten-
cilled cutout of the words ªO/D OFFº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. An
amber lens behind the cutout in the opaque layer of
the overlay causes the ªO/D OFFº text to appear in
amber through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED) soldered
onto the instrument cluster electronic circuit board.
The overdrive off indicator is serviced as a unit with
the instrument cluster.
OPERATION
The overdrive off indicator gives an indication to
the vehicle operator when the Off position of the
overdrive off switch has been selected, disabling the
electronically controlled overdrive feature of the auto-
matic transmission. This indicator is controlled by a
transistor on the instrument cluster circuit board
based upon the cluster programming and electronic
messages received by the cluster from the Powertrain
Control Module (PCM) over the Chrysler Collision
Detection (CCD) data bus. The overdrive off indicator
Light Emitting Diode (LED) receives battery current
on the instrument cluster electronic circuit board
through the fused ignition switch output (st-run) cir-
cuit whenever the ignition switch is in the On or
Start positions; therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
overdrive off indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the overdrive off indicator
is illuminated for about two seconds as a bulb test.
²Overdrive Off Lamp-On Message- Each time
the cluster receives an overdrive off lamp-on message
from the PCM indicating that the Off position of the
overdrive off switch has been selected, the overdrive
off indicator will be illuminated. The indicator
8J - 26 INSTRUMENT CLUSTERBR/BE
OIL PRESSURE GAUGE (Continued)

sage is not received after about four seconds, the
gauge needle will return to the far left (low) end of
the scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the crankshaft posi-
tion sensor to determine the engine speed, then
sends the proper engine speed messages to the
instrument cluster. For further diagnosis of the
tachometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the crankshaft position
sensor, the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the
tachometer, a DRBIIItscan tool is required. Refer to
the appropriate diagnostic information.
TRANS OVERTEMP
INDICATOR
DESCRIPTION
A transmission over-temperature indicator lamp is
standard equipment on all instrument clusters. How-
ever, on vehicles not equipped with the optional auto-
matic transmission, this indicator is electronically
disabled. The transmission over-temperature indica-
tor is located near the lower edge of the instrument
cluster overlay, to the left of center. The transmission
over-temperature indicator consists of a stencilled
cutout of the words ªTRANS TEMPº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. A red
lens behind the cutout in the opaque layer of the
overlay causes the ªTRANS TEMPº text to appear in
red through the translucent outer layer of the over-
lay when the indicator is illuminated from behind by
a Light Emitting Diode (LED) soldered onto the
instrument cluster electronic circuit board. The
transmission over-temperature indicator is serviced
as a unit with the instrument cluster.
OPERATION
The transmission over-temperature indicator gives
an indication to the vehicle operator when the trans-
mission fluid temperature is excessive, which may
lead to accelerated transmission component wear or
failure. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon the
cluster programming and electronic messagesreceived by the cluster from the Powertrain Control
Module (PCM) over the Chrysler Collision Detection
(CCD) data bus. The transmission over-temperature
indicator Light Emitting Diode (LED) receives bat-
tery current on the instrument cluster electronic cir-
cuit board through the fused ignition switch output
(st-run) circuit whenever the ignition switch is in the
On or Start positions; therefore, the LED will always
be off when the ignition switch is in any position
except On or Start. The LED only illuminates when
it is provided a path to ground by the instrument
cluster transistor. The instrument cluster will turn
on the transmission over-temperature indicator for
the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the transmission over-tem-
perature indicator is illuminated for about two sec-
onds as a bulb test.
²Trans Over-Temp Lamp-On Message- Each
time the cluster receives a trans over-temp lamp-on
message from the PCM indicating that the transmis-
sion fluid temperature is 135É C (275É F) or higher,
the indicator will be illuminated and a single chime
tone is sounded. The lamp remains illuminated until
the cluster receives a trans over-temp lamp-off mes-
sage from the PCM, or until the ignition switch is
turned to the Off position, whichever occurs first.
The chime tone feature will only repeat during the
same ignition cycle if the transmission over-tempera-
ture indicator is cycled off and then on again by the
appropriate trans over-temp messages from the PCM.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The PCM continually monitors the transmission
temperature sensor to determine the transmission
operating condition, then sends the proper messages
to the instrument cluster. If the instrument cluster
turns on the transmission over-temperature indicator
due to a high transmission oil temperature condition,
it may indicate that the transmission and/or the
transmission cooling system are being overloaded or
that they require service. For further diagnosis of the
transmission over-temperature indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). For proper
diagnosis of the transmission temperature sensor, the
PCM, the CCD data bus, or the message inputs to
the instrument cluster that control the transmission
over-temperature indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
BR/BEINSTRUMENT CLUSTER 8J - 31
TACHOMETER (Continued)

HEADLAMP RELAY
DESCRIPTION
The headlamp (or security) relay is located in the
Power Distribution Center (PDC) near the battery in
the engine compartment (Fig. 14). See the fuse and
relay layout label affixed to the inside surface of the
PDC cover for headlamp relay identification and loca-
tion. The headlamp relay is a conventional Interna-
tional Standards Organization (ISO) micro relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal 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 its PDC receptacle by
five male spade-type terminals that extend from the
bottom of the relay base. The ISO designation for
each terminal is molded into the base adjacent to the
terminal. The ISO terminal designations are as fol-
lows:
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 headlamp relay cannot be adjusted or
repaired. If the relay is damaged or faulty, it must be
replaced.
OPERATION
The headlamp (or security) relay is an electrome-
chanical switch that uses a low current input from
the high-line or premium Central Timer Module
(CTM) to control a high current output to the head-
lamps. 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 wind-
ings. 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 par-
allel with the relay coil in the relay, and helps to dis-
sipate voltage spikes and electromagnetic
interference that can be generated as the electromag-
netic field of the relay coil collapses.
The headlamp relay terminals are connected to the
vehicle electrical system through a connector recepta-
cle in the Power Distribution Center (PDC). The
inputs and outputs of the headlamp relay include:
²The common feed terminal (30) is connected to
ground at all times through a take out and eyelet
terminal connector of the right headlamp and dash
wire harness that is secured by a ground screw to
the left fender inner shield near the PDC in the
engine compartment.
²The coil ground terminal (85) is connected to the
Central Timer Module (CTM) through the security
relay control circuit. The CTM energizes the head-
lamp relay control coil by internally pulling this cir-
cuit to ground.
²The coil battery terminal (86) is connected to
battery current at all times through a fused B(+) cir-
cuit that is internal to the PDC.
²The normally open terminal (87) is connected to
the headlamps at all times through the beam select
switch low beam output circuit. This circuit provides
a path to ground for the headlamps through the com-
mon feed terminal when the headlamp relay control
coil is energized by the CTM.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but is
grounded through the common feed terminal when
the headlamp relay control coil is de-energized.
The headlamp relay can be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - HEADLAMP RELAY
The headlamp (or security) relay (Fig. 15) is
located in the Power Distribution Center (PDC) near
the battery in the engine compartment. See the fuse
and relay layout label affixed to the inside surface of
Fig. 14 Power Distribution Center
1 - COVER
2 - POWER DISTRIBUTION CENTER
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 17

LAMPS/LIGHTING - INTERIOR
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - INTERIOR
SPECIFICATIONS
INTERIOR LAMPS.....................33
DOME LAMP
REMOVAL.............................34
INSTALLATION.........................34
DOOR AJAR SWITCH
DESCRIPTION.........................34
DIAGNOSIS AND TESTING - DOOR AJAR
SWITCH............................34
REMOVAL.............................35
INSTALLATION.........................35GLOVE BOX LAMP AND SWITCH
REMOVAL.............................35
INSTALLATION.........................36
READING LAMP
DESCRIPTION.........................36
OPERATION...........................36
REMOVAL.............................36
INSTALLATION.........................37
VANITY LAMP
REMOVAL.............................37
INSTALLATION.........................37
LAMPS/LIGHTING - INTERIOR
SPECIFICATIONS
INTERIOR LAMPS
LAMP BULB
A/C HEATER CONTROL 158
ASH RECEIVER 161
CIGAR LIGHTER 161
HEADLAMP SWITCH 158
HEATER CONTROL 158
INSTRUMENT CLUSTER PC194
RADIO ASC
AIRBAG HIGH LINE PC194
AIRBAG LOW LINE PC74
ANTI-LOCK BRAKE PC74
BATTERY VOLTAGE PC194
BRAKE WARNING PC194LAMP BULB
CHECK ENGINE PC74
ENGINE OIL PRESSURE PC74
FOUR WHEEL DRIVE PC194
HIGH BEAM PC194
LOW FUEL PC194
LOW WASHER FLUID PC74
MAINTENANCE
REQUIREDPC74
MESSAGE CENTER PC194
SEAT BELT PC74
TURN SIGNAL PC194
UPSHIFT PC74
DOME 1004
GLOVE COMPARTMENT 1891
VANITY MIRROR LAMP P/N 6501966
BR/BELAMPS/LIGHTING - INTERIOR 8L - 33

(2) Reconnect the headlamp and dash wire harness
ground connector to the wiper motor ground terminal
(Fig. 9).
(3) Reconnect the headlamp and dash wire harness
connector for the wiper motor to the wiper motor pig-
tail wire connector.
(4) Reach into the cowl plenum to align the wiper
module mounting bracket with the locations for the
mounting screws (Fig. 8).
(5) Install and tighten the four screws that secure
the wiper module bracket to the cowl plenum panel
and the dash panel. Tighten the screws to 8 N´m (72
in. lbs.).
(6) Reinstall the cowl plenum cover/grille panel
onto the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(7) Reinstall the wiper arms onto the wiper pivots.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARMS - INSTALLATION).
(8) Reconnect the battery negative cable.
WIPER RELAY
DESCRIPTION
The wiper relay (or intermittent wipe relay) is
located in the Power Distribution Center (PDC) near
the battery in the engine compartment. See the fuse
and relay layout label affixed to the inside surface of
the PDC cover for wiper relay identification and loca-
tion. The wiper relay is a conventional International
Standards Organization (ISO) micro relay. Relays
conforming to the ISO specifications have common
physical dimensions, current capacities, terminal pat-
terns, and terminal functions. The relay is containedwithin a small, rectangular, molded plastic housing.
The relay is connected to all of the required inputs
and outputs through its PDC receptacle by five male
spade-type terminals that extend from the bottom of
the relay base. The ISO designation for each termi-
nal is molded into the base adjacent to the terminal.
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 Central Timer Module (CTM) to con-
trol 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 con-
tact 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 nor-
mally closed contact point, and holds it against the
fixed normally open contact point. When the relay
coil is de-energized, spring pressure returns the mov-
able 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 inter-
ference 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 Power Distribution Center (PDC). The
inputs and outputs of the wiper relay include:
²The common feed terminal (30) is connected 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-ener-
gized, the common feed terminal is connected to the
wiper park switch output through the wiper park
switch sense circuit. The wiper park switch output
may be battery current (wipers are not parked), or
ground (wipers are parked). When the wiper relay is
energized, the common feed terminal of the wiper is
Fig. 9 Wiper Module Electrical Connections
1 - GROUND CONNECTOR
2 - WIPER MOTOR CONNECTOR
3 - GROUND TERMINAL
BR/BEWIPERS/WASHERS 8R - 15
WIPER MODULE (Continued)

connected to battery current from a fuse in the Junc-
tion Block (JB) through a fused ignition switch out-
put (run-acc) circuit.
²The coil ground terminal (85) is connected to the
relay control output of the CTM through the wiper
motor relay control circuit. The CTM controls the
ground path for this circuit internally to energize or
de-energize the wiper relay based upon its program-
ming and inputs from the wiper and washer control
circuitry of the multi-function switch and from the
wiper motor park switch.
²The coil battery terminal (86) is connected to
battery current from a fuse in the Junction Block
(JB) through a fused ignition switch output (run-acc)
circuit whenever the ignition switch is in the On or
Accessory positions.
²The normally open terminal (87) is connected to
battery current from a fuse in the Junction Block
(JB) through a fused ignition switch output (run-acc)
circuit whenever the wiper relay control coil is ener-
gized by the CTM. This circuit provides fused igni-
tion switch output (run-acc) current to the wiper
motor low speed brush only when the wiper relay
control coil is energized.
²The normally closed terminal (87A) is connected
to the output of the wiper motor park switch through
the wiper motor park switch sense circuit. This cir-
cuit provides battery current (wipers are not parked)
or ground (wipers are parked) to the wiper motor low
speed brush whenever the wiper relay control coil is
de-energized and the Off position of the wiper control
of the multi-function switch is selected.
The wiper relay can be diagnosed using conven-
tional diagnostic tools and methods.
DIAGNOSIS AND TESTING - WIPER RELAY
The wiper relay (or intermittent wipe relay) (Fig.
10) is located in the Power Distribution Center (PDC)
in the engine compartment. See the fuse and relay
layout label affixed to the inside surface of the PDC
cover for wiper relay identification and location.
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.
(1) Remove the wiper relay from the PDC. (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WIPER
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   5 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, test the relay input and output cir-
cuits. Refer to RELAY CIRCUIT TEST . If not OK,
replace the faulty relay.
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to the multi-function switch. There should
be continuity between the receptacle for terminal 30
of the wiper relay in the PDC and both driver low
speed wiper motor driver circuit cavities of the
instrument panel wire harness connector for the
multi-function switch at all times. If OK, go to Step
2. If not OK, repair the open driver low speed wiper
motor driver circuit(s) between the PDC and the
multi-function switch as required.
(2) The relay normally closed terminal (87A) is
connected to the wiper motor park switch through
the wiper motor park switch sense circuit. There
should be continuity between the receptacle for ter-
minal 87A of the wiper relay in the PDC and the
wiper motor park switch sense circuit cavity of the
headlamp and dash wire harness connector for the
wiper motor at all times. If OK, go to Step 3. If not
OK, repair the open wiper motor park switch sense
circuit between the PDC and the wiper motor as
required.
(3) The relay normally open terminal (87) is con-
nected to a fused ignition switch output (run-acc)
fuse in the Junction Block (JB) through a fused igni-
tion switch output (run-acc) circuit. There should be
battery voltage at the receptacle for terminal 87 of
Fig. 10 Wiper Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8R - 16 WIPERS/WASHERSBR/BE
WIPER RELAY (Continued)

8W-02 COMPONENT INDEX
Component Page
4WD Switch.......................... 8W-31
A/C Compressor Clutch Relay............ 8W-42
A/C Compressor Clutch................. 8W-42
A/C- Heater Control.................... 8W-42
A/C Heater Temperature Select........... 8W-42
A/C High Pressure Switch............... 8W-42
A/C Low Pressure Switch................ 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Aftermarket Center High Mounted Stop
Lamp............................. 8W-51
Aftermarket Trailer Tow Connector........ 8W-54
Airbag Control Module.................. 8W-43
Ambient Temperature Sensor............ 8W-49
Ash Receiver Lamp.................... 8W-44
Automatic Day/Night Mirror............. 8W-49
Automatic Shut Down Relay............. 8W-30
Auxiliary Battery...................... 8W-20
Back-Up Lamp Switch.................. 8W-51
Back-Up Lamp........................ 8W-51
Battery Temperature Sensor............. 8W-30
Battery............................. 8W-20
Blend Door Actuator................... 8W-42
Blower Motor Relay.................... 8W-42
Blower Motor Resistor Block............. 8W-42
Blower Motor......................... 8W-42
Brake Lamp Switch.................... 8W-51
Brake Pressure Switch............... 8W-34, 35
Bypass Jumper....................... 8W-21
Camshaft Position Sensor............... 8W-30
Capacitor......................... 8W-10, 30
Cargo Lamps........................ 8W-44
Center High Mounted Stop Lamps........ 8W-51
Center Identification Lamp.............. 8W-50
Central Timer Module.................. 8W-45
Cigar Lighter......................... 8W-41
Circuit Breakers...................... 8W-12
Clockspring.................. 8W-33, 41, 43, 47
Clutch Pedal Position Switch............. 8W-21
Combination Flasher................... 8W-52
Controller Antilock Brake............ 8W-34, 35
Crankshaft Position Sensor.............. 8W-30
Cummins Bus........................ 8W-18
Cup Holder Lamp..................... 8W-44
Data Link Connector................... 8W-18
Daytime Running Lamp Module.......... 8W-50
Dome Lamp.......................... 8W-44
Driver Airbag......................... 8W-43
Driver Cylinder Lock Switch............. 8W-39
Driver Door Ajar Switch................ 8W-45
Driver Door Lock Motor................. 8W-61
Driver Door Window/Lock Switch...... 8W-60, 61
Driver Heated Seat Cushion............. 8W-63Component Page
Driver Heated Seat Switch.............. 8W-63
Driver Lumbar Motor.................. 8W-63
Driver Power Seat Front Vertical Motor.... 8W-63
Driver Power Seat Horizontal Motor....... 8W-63
Driver Power Seat Rear Vertical Motor..... 8W-63
Driver Power Seat Switch............... 8W-63
Driver Power Window Motor............. 8W-60
Electric Brake Provision................ 8W-54
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor....... 8W-30
Engine Oil Pressure Sensor.............. 8W-30
Engine Starter Motor Relay.............. 8W-21
Engine Starter Motor................... 8W-21
EVAP/Purge Solenoid................... 8W-30
Fender Lamp......................... 8W-51
Fog Lamp Relay....................... 8W-50
Fog Lamp............................ 8W-50
Fuel Heater Relay..................... 8W-30
Fuel Heater........................ 8W-30-36
Fuel Injection Pump................... 8W-30
Fuel Injectors......................... 8W-30
Fuel Pump Module.................... 8W-30
Fuel Pump Relay...................... 8W-30
Fuel Tank Module..................... 8W-30
Fuel Transfer Pump.................... 8W-30
Fuses (JB)........................... 8W-12
Fuses (PDC).......................... 8W-10
Fusible Link....................... 8W-20, 30
Grounds............................. 8W-15
Generator............................ 8W-20
Glove Box Lamp And Switch............. 8W-44
Headlamp Beam Select Switch........... 8W-50
Headlamp Switch...................... 8W-50
Headlamp........................... 8W-50
Heated Mirror Relay................... 8W-62
Heated Mirror Switch.................. 8W-62
Heated Seat Relay..................... 8W-12
High Note Horn....................... 8W-41
Horn Relay.......................... 8W-41
Horn Switch.......................... 8W-41
Idle Air Control Motor.................. 8W-30
Ignition Coils......................... 8W-30
Ignition Switch....................... 8W-10
Instrument Cluster.................... 8W-40
Intake Air Heater Relays................ 8W-30
Intake Air Heater..................... 8W-30
Intake Air Temperature Sensor........... 8W-30
Intermittent Wiper Switch............... 8W-53
Joint Connectors....... 8W-10, 12, 15, 30, 34, 35,
40, 44, 45, 51, 53, 54, 70
Junction Block........................ 8W-12
Leak Detection Pump.................. 8W-30
BR/BE8W-02 COMPONENT INDEX 8W - 02 - 1

8W-10 POWER DISTRIBUTION
Component Page
A/C Compressor Clutch................ 8W-10-27
A/C Compressor Clutch Relay......... 8W-10-9, 27
Aftermarket Center High Mounted Stop
Lamp........................... 8W-10-13
Aftermarket Trailer Tow Connector....... 8W-10-21
Automatic Shut Down Relay.......... 8W-10-14, 20
Auxiliary Battery..................... 8W-10-8
Battery............................. 8W-10-8
Blower Motor....................... 8W-10-23
Blower Motor Relay................. 8W-10-8, 23
Brake Lamp Switch................. 8W-10-8, 13
Capacitor.......................... 8W-10-16
Center High Mounted Stop Lamp No. 1.... 8W-10-13
Center High Mounted Stop Lamp No. 2.... 8W-10-13
Central Timer Module.............. 8W-10-22, 26
Circuit Breaker 2.................... 8W-10-10
Clockspring......................... 8W-10-26
Combination Flasher.................. 8W-10-13
Controller Antilock Brake.............. 8W-10-23
Daytime Running Lamp Module......... 8W-10-25
Electric Brake Provision............. 8W-10-13, 21
Engine Control Module................ 8W-10-12
Engine Starter Motor................. 8W-10-23
Engine Starter Motor Relay........... 8W-10-8, 23
Fog Lamp Relay..................... 8W-10-25
Fuel Heater........................ 8W-10-20
Fuel Heater Relay.................. 8W-10-8, 20
Fuel Injection Pump.................. 8W-10-12
Fuel Injector No. 1................. 8W-10-15, 16
Fuel Injector No. 2................. 8W-10-15, 16
Fuel Injector No. 3................. 8W-10-15, 16
Fuel Injector No. 4................. 8W-10-15, 16
Fuel Injector No. 5................. 8W-10-15, 16
Fuel Injector No. 6................. 8W-10-15, 16
Fuel Injector No. 7................. 8W-10-15, 16
Fuel Injector No. 8................. 8W-10-15, 16
Fuel Injector No. 9................... 8W-10-16
Fuel Injector No. 10................... 8W-10-16
Fuel Pump Module................... 8W-10-11
Fuel Pump Relay.................. 8W-10-11, 12
Fuse 1 (JB)......................... 8W-10-10
Fuse 1 (PDC)...................... 8W-10-8, 10
Fuse 2 (PDC)................... 8W-10-8, 10, 22
Fuse 3 (PDC)................... 8W-10-8, 11, 12
Fuse 4 (JB)......................... 8W-10-10
Fuse 4 (PDC)...................... 8W-10-8, 13
Fuse 5 (PDC)...................... 8W-10-8, 13
Fuse 6 (PDC)................... 8W-10-8, 14, 20
Fuse 7 (PDC)...................... 8W-10-8, 20
Fuse 8 (PDC)...................... 8W-10-8, 21
Fuse 9 (PDC)...................... 8W-10-8, 23
Fuse 10 (PDC)..................... 8W-10-8, 22
Fuse 11 (PDC)..................... 8W-10-8, 23
Fuse 12 (JB)........................ 8W-10-10
Fuse 12 (PDC)................... 8W-10-8, 9, 23
Fuse 13 (JB)........................ 8W-10-10
Component Page
Fuse 14 (JB)........................ 8W-10-10
Fuse B (PDC)................... 8W-10-8, 9, 24
Fuse C (PDC)..................... 8W-10-9, 24
Fuse E (PDC)..................... 8W-10-9, 24
Fuse F (PDC)..................... 8W-10-9, 24
Fuse G (PDC)..................... 8W-10-9, 25
Fuse H (PDC)..................... 8W-10-9, 26
Fuse I (PDC)...................... 8W-10-9, 26
Fuse J (PDC)...................... 8W-10-9, 27
Fuse K (PDC)............. 8W-10-9, 14, 17, 18, 19
Fuse L (PDC)..................... 8W-10-9, 27
Fuse Gen (PDC)................... 8W-10-8, 27
G201............................. 8W-10-22
Generator........................ 8W-10-8, 27
Headlamp Beam Select Switch........... 8W-10-25
Headlamp Switch.................. 8W-10-9, 24
High Note Horn..................... 8W-10-26
Horn Relay....................... 8W-10-9, 26
Ignition Coil........................ 8W-10-15
Ignition Coil 4 Pack................... 8W-10-16
Ignition Coil 6 Pack................... 8W-10-16
Ignition Switch................. 8W-10-8, 10, 22
Joint Connector No. 1.............. 8W-10-25, 26
Joint Connector No. 2........ 8W-10-8, 9, 11, 12, 14,
15, 16, 20, 21
Joint Connector No. 5................. 8W-10-22
Joint Connector No. 6............ 8W-10-13, 22, 26
Joint Connector No. 8................. 8W-10-22
Junction Block.................. 8W-10-8, 10, 13
Left Fog Lamp...................... 8W-10-25
Left Headlamp...................... 8W-10-24
Left Outboard Headlamp.......... 8W-10-9, 24, 25
Low Note Horn...................... 8W-10-26
Oxygen Sensor 1/1 Left Bank Up . . . 8W-10-17, 18, 19
Oxygen Sensor 1/1 Upstream............ 8W-10-17
Oxygen Sensor 1/2 Downstream.......... 8W-10-17
Oxygen Sensor 1/2 Left Bank Down....... 8W-10-19
Oxygen Sensor 1/2 Pre-Catalyst.......... 8W-10-18
Oxygen Sensor 1/3 Post-Catalyst......... 8W-10-18
Oxygen Sensor 2/1 Right Bank Up . . 8W-10-17, 18, 19
Oxygen Sensor 2/2 Right Bank Down...... 8W-10-19
Oxygen Sensor Downstream Relay..... 8W-10-18, 19
Power Distribution Center.... 8W-10-8, 9, 10, 11, 12,
13, 14, 2, 20, 21, 22, 23, 24, 25, 26, 27
Power Outlet...................... 8W-10-9, 27
Powertrain Control Module . . 8W-10-11, 12, 15, 16, 20
Quad High Beam Relay................ 8W-10-24
Right Fog Lamp..................... 8W-10-25
Right Headlamp..................... 8W-10-24
Right Outboard Headlamp......... 8W-10-9, 24, 25
Security Relay..................... 8W-10-9, 25
Trailer Tow Connector................. 8W-10-21
Trailer Tow Relay.................... 8W-10-21
Transmission Control Relay........... 8W-10-9, 26
Transmission Solenoid Assembly......... 8W-10-26
Turn Signal/Hazard Switch............. 8W-10-13
BR/BE8W-10 POWER DISTRIBUTION 8W - 10 - 1