Rear seat DODGE RAM 1500 1998 2.G Service Manual

HEATED SYSTEMS
TABLE OF CONTENTS
page page
HEATED GLASS........................... 1
HEATED MIRRORS......................... 6HEATED SEAT SYSTEM..................... 7
HEATED GLASS
TABLE OF CONTENTS
page page
HEATED GLASS
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SYSTEM...................2
REAR WINDOW DEFOGGER RELAY
DESCRIPTION..........................2
OPERATION............................3REMOVAL.............................3
INSTALLATION..........................4
REAR WINDOW DEFOGGER SWITCH
DESCRIPTION..........................4
OPERATION............................4
REAR WINDOW DEFOGGER GRID
STANDARD PROCEDURE - GRID LINE AND
TERMINAL REPAIR.....................4
HEATED GLASS
DESCRIPTION
CAUTION:Grid lines can be damaged or scraped off
with sharp instruments. Care should be taken in
cleaning glass or removing foreign materials, decals
or stickers. Normal glass cleaning solvents or hot
water used with rags or toweling is recommended.
The rear window defogger system consists of a
back glass with two vertical electrical bus bars linked
by a series of grid lines fired onto the inside surface
of the optional heated rear window.
The rear window defogger system is turned On or
Off by a switch and a timing circuit integral to the
A/C-heater control located at the center of the instru-
ment panel.
Circuit protection is provided by a cartridge fuse
located in the power distribution center (PDC) for the
heated grid circuit, and a fuse located in the fuse
block for the control circuit.
OPERATION
The rear window defogger system is turned on by a
momentary switch located in the A/C-heater control
on the instrument panel. When the rear windowdefogger switch is pressed to the On position, current
is directed through the rear window defogger relay to
the rear defogger grid lines. The heated grid lines
heat the rear glass to help clear the rear window sur-
face of fog or frost.
A yellow indicator above the switch will illuminate
to indicate when the rear window defogger system is
turned on. The A/C-heater control contains the rear
window defogger system control circuitry.
NOTE: The rear window defogger turns off automat-
ically after approximately 10 minutes of initial oper-
ation. Each following activation cycle of the
defogger system will last approximately ten minutes
also.
The rear window defogger system will be automat-
ically turned off after a programmed time interval of
about ten minutes. After the initial time interval has
expired, if the defogger switch is pressed to the On
position again during the same ignition cycle, the
rear window defogger system will automatically turn
off after about ten minutes also.
The rear window defogger system will automati-
cally shut off if the ignition switch is turned to the
Off position, or it can be turned off manually by
pressing the defogger switch a second time.
DRHEATED SYSTEMS 8G - 1

INSTALLATION
(1) Refer to the fuse and relay layout map on the
inner surface of the integrated power module (IPM)
for rear window defogger relay identification and
location.
(2) Position the rear window defogger relay into
the proper receptacle in the IPM.
(3) Align the rear window defogger relay terminals
with the terminal cavities in the IPM receptacle.
(4) Push down firmly on the rear window defogger
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install the cover onto the IPM.
(6) Reconnect the negative battery cable.
REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is integrated into
the A/C-heater control mounted in the center of the
instrument panel. The rear window defogger switch
and the rear window defogger LED indicator cannot
be repaired and, if faulty or damaged, the A/C-heater
control must be replaced.
OPERATION
An LED indicator will illuminate when the rear
window defogger switch is activated. The switch
energizes the timing circuit integral to the A/C-
heater control which then activates the rear window
defogger relay. The rear window defogger relay con-
trols the current to flow to the grids of the rear win-
dow defogger. The rear window defogger system will
operate for approximately ten minutes or until the
rear window defogger switch or ignition switch is
turned off. Refer to 8 - ELECTRICAL/HEATED
GLASS - DIAGNOSIS AND TESTING for diagnosis
and testing of the rear window defogger switch.
The rear window defogger switch cannot be
repaired and, if faulty or damaged, it must be
replaced. (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/A/C HEATER CONTROL -
REMOVAL).
REAR WINDOW DEFOGGER
GRID
STANDARD PROCEDURE - GRID LINE AND
TERMINAL REPAIR
REAR WINDOW DEFOGGER GRID LINE REPAIR
WARNING: THE REPAIR KIT CONTAINS EPOXY
RESIN AND AMINE TYPE HARDENER WHICH MAY
CAUSE SKIN OR EYE IRRITATION AND CAN BE
HARMFUL IF SWALLOWED. USE WITH ADEQUATE
VENTILATION. DO NOT USE NEAR FIRE OR OPEN
FLAME THE CONTENTS CONTAIN FLAMMABLE
SOLVENTS. KEEP OUT OF REACH OF CHILDREN.
²DO NOT TAKE INTERNALLY, IF SWALLOWED
INDUCE VOMITING AND CALL A PHYSICIAN IMME-
DIATELY.
²IF SKIN CONTACT OCCURS, WASH AFFECTED
AREAS WITH SOAP AND WATER.
²IF EYE CONTACT OCCURS, FLUSH WITH
PLENTY OF WATER.
The repair of the grid lines is possible using the
MopartGrid Line Repair Package or an equivalent.
(1) Mask the repair area so the conductive epoxy
can be extended onto the grid line(s) or the bus bar
(Fig. 4).
(2) Follow the instructions in the repair kit for
preparing the damaged area.
(3) Remove the package separator clamp and mix
the conductive epoxy thoroughly. Fold in half and cut
the center corner to dispense the epoxy.
(4) Apply the conductive epoxy through the slit in
the masking tape. Overlap both ends of the break(s)
by 19 mm (3/4 inch).
(5) Carefully remove the masking tape from the
grid line(s).
CAUTION: To prevent the glass from fracturing, do
not allow the glass surface to exceed 204É C (400É
F).
(6) Allow the epoxy to cure 24 hours at room tem-
perature or use a heat gun with a 260É to 371É C
(500É to 700É F) range for 15 minutes. Hold the heat
gun approximately 254 mm (10 inches) from the
repaired area.
(7) After the conductive epoxy is properly cured,
verify operation of the rear window defogger.
8G - 4 HEATED GLASSDR
REAR WINDOW DEFOGGER RELAY (Continued)

(5) Install the appropriate seat cushion or seat
back trim cover. Make certain the seat wire harness
is correctly routed through the seat and seat back.
HEATED SEAT SENSOR
DESCRIPTION
The heated seat temperature sensor is a Negative
Temperature Coefficient (NTC) thermistor. One tem-
perature sensor is used for each seat. This tempera-
ture sensor is located in the seat cushion heating
element on all models.
The heated seat temperature sensor cannot be
repaired or adjusted and must be replaced if defec-
tive. The heated seat cushion element must be
replaced if the temperature sensor is defective. Refer
to the procedure in this section of the service man-
ual.
OPERATION
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
heated seat module supplies five-volts to one side of
each sensor, and monitors the voltage drop through
the sensor on a return circuit. The heated seat mod-
ule uses this temperature sensor input to monitor
the temperature of the seat, and regulates the cur-
rent flow to the seat heating elements accordingly.
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR
NOTE: Any resistance values (OHMSV) given in the
following text are supplied using the automatic
range generated by a FLUKETautomotive meter. If
another type of measuring device is used, the val-
ues generated may not be the same as the results
shown here, or may have to be converted to the
range used here.
(1) Position the driver seat in the full rearward
position.
(2) Unclip the heated seat module from the bottom
of the drivers seat cushion pan.
(3) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity (#7
for passenger, #8 for driver seat) for a range in volt-
age from approx. 1.72 ± 3.0 volts. It should be within
this range, If OK check the heated seat element. If
NOT OK, check for the proper 5 volt supply to the
heated seat sensor, from the module. Refer to Wiring
for specific information. If 5 volts is not being sup-
plied to the sensor from the module, replace the
heated seat module.
(4) Test the seat wire harness between the heated
seat module connector and the heated seat wire har-
ness connector for shorted or open circuits. If OK,
refer toDiagnosis and Testing the Heated Seat
Modulein Electronic Control Modules, for the
proper heated seat module diagnosis and testing pro-
cedures. If not OK, repair the shorted or open heated
seat wire harness as required.
REMOVAL
(1) For heated seat sensor replacement procedure
(Refer to 8 - ELECTRICAL/HEATED SEATS/
HEATED SEAT ELEMENT - REMOVAL).
HEATED SEAT SWITCH
DESCRIPTION
The momentary, bidirectional rocker-type heated
seat switch (Fig. 4) provides a resistor-multiplexed
signal to the heated seat module via a mux circuit.
Each switch has a center neutral position and
momentary Low and High positions so that both the
driver and the front seat passenger can select a pre-
ferred level of seat heating. Each heated seat switch
has two Light-Emitting Diode (LED) indicator lamps,
which indicate the selected mode (Low or High) of
the seat heater. These indicator lamps also provide
diagnostic feedback for the heated seat system. Each
switch also has an incandescent bulb, which provides
Fig. 3 Heating Element Installation
1 - ORIGINAL (INOPERATIVE) HEATING ELEMENT
2 - REPLACEMENT HEATING ELEMENT
DRHEATED SEAT SYSTEM 8G - 11
HEATED SEAT ELEMENT (Continued)

should be present. If OK go to Step 5, if Not, Repair
the open or shorted voltage supply circuit as
required.
(5) Using a ohmmeter, backprobe the appropriate
heated seat module connector, do not disconnect.
Check for proper continuity to ground on the ground
pin cavities. Continuity should be present. If OK
replace the heated seat module with a known good
unit and retest system, if Not OK, Repair the open or
shorted ground circuit as required.
REMOVAL
(1) Position the driver seat to the full rearward
and inclined position.
(2) Working under the driver front seat, remove
the two heated seat module retaining screws. Due to
the fact that the retaining screws are installed with
the seat cushion pan removed, a small right angle
screwdriver will be required to access and remove the
screws.(3) Disconnect the seat wire harness connector
from the connector receptacle on the back of the
heated seat module. Depress the connector retaining
tab and pull straight apart.
(4) Remove the heated seat module from under the
front seat.
INSTALLATION
(1) Position the heated seat module under the
front seat.
(2) Connect the seat wire harness connector on the
connector receptacle on the back of the heated seat
module.
(3) Working under the driver front seat, install the
heated seat module retaining screws.
(4) Re-position the driver seat.
DRHEATED SEAT SYSTEM 8G - 15
HEATED SEAT MODULE (Continued)

for more than about 1.6 kilometers (one mile) and
the vehicle speed remains greater than about twenty-
four kilometers-per-hour (fifteen miles-per-hour).
²Vacuum Fluorescent Display Synchroniza-
tion- The EMIC transmits electronic panel lamp
dimming level messages which allows all other elec-
tronic modules on the PCI data bus with Vacuum
Fluorescent Display (VFD) units to coordinate their
illumination intensity with that of the EMIC VFD
units.
²Vehicle Theft Security System- The EMIC
monitors inputs from the door cylinder lock
switch(es), the door ajar switches, the ignition
switch, and the Remote Keyless Entry (RKE) receiver
module, then provides electronic horn and lighting
request messages to the Front Control Module (FCM)
located on the Integrated Power Module (IPM) for
the appropriate VTSS alarm output features.
²Wiper/Washer System Control- The EMIC
provides electronic wiper and/or washer request mes-
sages to the Front Control Module (FCM) located on
the Integrated Power Module (IPM) for the appropri-
ate wiper and washer system features. (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS - DESCRIP-
TION).
The EMIC houses six analog gauges and has pro-
visions for up to twenty-three indicators (Fig. 3) or
(Fig. 4). The EMIC includes the following analog
gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Oil Pressure Gauge
²Speedometer
²Tachometer
²Voltage Gauge
Some of the EMIC indicators are automatically
configured when the EMIC is connected to the vehi-
cle electrical system for compatibility with certain
optional equipment or equipment required for regula-
tory purposes in certain markets. While each EMIC
may have provisions for indicators to support every
available option, the configurable indicators will not
be functional in a vehicle that does not have the
equipment that an indicator supports. The EMIC
includes provisions for the following indicators (Fig.
3) or (Fig. 4):
²Airbag Indicator (with Airbag System only)
²Antilock Brake System (ABS) Indicator
(with ABS or Rear Wheel Anti-Lock [RWAL]
brakes only)
²Brake Indicator
²Cargo Lamp Indicator
²Check Gauges Indicator
²Cruise Indicator (with Speed Control only)
²Door Ajar Indicator²Electronic Throttle Control (ETC) Indicator
(with 5.7L Gasoline Engine only)
²Gear Selector Indicator (with Automatic
Transmission only)
²High Beam Indicator
²Lamp Out Indicator
²Low Fuel Indicator
²Malfunction Indicator Lamp (MIL)
²Seatbelt Indicator
²Security Indicator (with Sentry Key Immo-
bilizer & Vehicle Theft Security Systems only)
²Service Four-Wheel Drive Indicator (with
Four-Wheel Drive only)
²Tow/Haul Indicator (with Automatic Trans-
mission only)
²Transmission Overtemp Indicator (with
Automatic Transmission only)
²Turn Signal (Right and Left) Indicators
²Upshift Indicator (with Manual Transmis-
sion only)
²Washer Fluid Indicator
²Wait-To-Start Indicator (with Diesel Engine
only)
²Water-In-Fuel Indicator (with Diesel Engine
only)
Each indicator in the EMIC, except those located
within one of the VFD units, is illuminated by a ded-
icated LED that is soldered onto the EMIC electronic
circuit board. The LED units are not available for
service replacement and, if damaged or faulty, the
entire EMIC must be replaced. Cluster illumination
is accomplished by dimmable incandescent back
lighting, which illuminates the gauges for visibility
when the exterior lighting is turned on. Each of the
incandescent bulbs is secured by an integral bulb
holder to the electronic circuit board from the back of
the cluster housing.
Hard wired circuitry connects the EMIC to the
electrical system of the vehicle. These hard wired cir-
cuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system
and to the EMIC 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.
The EMIC modules for this model are serviced only
as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator, a
VFD unit, the electronic circuit board, the circuit
DRINSTRUMENT CLUSTER 8J - 5
INSTRUMENT CLUSTER (Continued)

INPUT AND OUTPUT CIRCUITS
HARD WIRED INPUTS
The hard wired inputs to the EMIC include the fol-
lowing:
²Brake Lamp Switch Output
²Driver Cylinder Lock Switch Sense
²Driver Door Ajar Switch Sense
²Driver Door Lock Switch MUX - with
Power Locks
²Fused B(+) - Ignition-Off Draw
²Fused B(+) - Power Lock Feed - with Power
Locks
²Fused Ignition Switch Output (Accessory-
Run)
²Fused Ignition Switch Output (Off-Run-
Start)
²Fused Ignition Switch Output (Run-Start)
²Headlamp Dimmer Switch MUX
²Headlamp Switch MUX
²Horn Relay Control
²Key-In Ignition Switch Sense
²Left Rear Door Ajar Switch Sense
²Panel Lamps Dimmer Switch Signal
²Park Brake Switch Sense
²Passenger Door Ajar Switch Sense
²Passenger Door Lock Switch MUX - with
Power Locks
²Radio Control MUX
²Right Rear Door Ajar Switch Sense
²RKE Supply - with RKE
²Seat Belt Switch Sense
²Transmission Range Sensor MUX - with
Auto Trans
²Turn/Hazard Switch MUX
²Washer/Beam Select Switch MUX
²Wiper Switch MUX
Refer to the appropriate wiring information for
additional details.
HARD WIRED OUTPUTS
The hard wired outputs of the EMIC include the
following:
²Accessory Switch Bank Illumination Driver
²BTSI Driver - with Auto Trans
²Cargo Lamp Driver
²Dome/Overhead Lamp Driver
²Driver Door Unlock Driver - with Power
Locks
²Headlamp Switch Illumination Driver
²Heated Seat Switch Indicator Driver - with
Heated Seats
²Heater-A/C Control Illumination Driver
²Left Door Lock Driver - with Power Locks
²Left Rear Door Unlock Driver - with Power
Locks²Map/Glove Box Lamp Driver
²Radio Illumination Driver
²Right Door Lock Driver - with Power Locks
²Right Door Unlock Driver - with Power
Locks
²Transfer Case Switch Illumination Driver -
with Four-Wheel Drive
Refer to the appropriate wiring information for
additional details.
GROUNDS
The EMIC receives and supplies a ground path to
several switches and sensors through the following
hard wired circuits:
²Ground - Illumination (2 Circuits)
²Ground - Power Lock - with Power Locks
²Ground - Signal
²Headlamp Switch Return
²Multi-Function Switch Return
²Transmission Range Sensor Return - with
Auto Trans
Refer to the appropriate wiring information for
additional details.
COMMUNICATION
The EMIC has provisions for the following commu-
nication circuits:
²PCI Data Bus
²RKE Program Serial Data - with RKE
²RKE Transmit Serial Data - with RKE
Refer to the appropriate wiring information for
additional details.
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER
If all of the instrument cluster gauges and/or indi-
cators are inoperative, refer to PRELIMINARY
DIAGNOSIS. If an individual gauge or Programma-
ble Communications Interface (PCI) data bus mes-
sage-controlled indicator is inoperative, refer to
ACTUATOR TEST. If an individual hard wired indi-
cator is inoperative, refer to the diagnosis and testing
information for that specific indicator.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
8J - 10 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

INSTRUMENT CLUSTER FAILURE MESSAGE
Fault Code Description Correction
AC ABS messages not received. Refer to the appropriate diagnostic information.
AD FCM messages not received. Refer to the appropriate diagnostic information.
AE ACM messages not received. Refer to the appropriate diagnostic information.
AF SKIM messages not received. Refer to the appropriate diagnostic information.
B0 RKE fob batteries low. Refer to the appropriate diagnostic information.
B1 RKE module communication link. Refer to the appropriate diagnostic information.
00 Done All Diagnostic Trouble Codes (DTC) have been
displayed.
(7) The actuator test is now completed. The instru-
ment cluster will automatically exit the self-diagnos-
tic mode and return to normal operation at the
completion of the test, if the ignition switch is turned
to the Off position during the test, or if a vehicle
speed message indicating that the vehicle is moving
is received from the PCM over the PCI data bus dur-
ing the test.
(8) Go back to Step 1 to repeat the test, if neces-
sary.
REMOVAL
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(3) Remove the four screws that secure the instru-
ment cluster to the instrument panel structural sup-
port (Fig. 5).
(4) Pull the instrument cluster rearward far
enough to access and disconnect the instrument
panel wire harness connectors for the cluster fromthe connector receptacles on the back of the cluster
housing.
(5) Remove the instrument cluster from the instru-
ment panel.
DISASSEMBLY
Some of the components for the instrument cluster
used in this vehicle are serviced individually. The
serviced components include the incandescent instru-
ment cluster illumination lamp bulbs (including the
integral bulb holders), and the cluster lens, hood and
mask unit. Following are the procedures for disas-
sembling these components from the instrument clus-
ter unit.
Fig. 5 Instrument Cluster Remove/Install
1 - WIRE HARNESS CONNECTOR (3)
2 - INSTRUMENT CLUSTER
3 - SCREW (4)
4 - INSTRUMENT PANEL STRUCTURAL SUPPORT
8J - 14 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

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.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp bulb and bulb holder units.
If the vehicle is equipped with the optional Remote
Keyless Entry (RKE) system, the RKE receiver mod-
ule must be removed from the instrument cluster
rear cover to access the lower center cluster illumi-
nation lamp, which is located on the circuit board
directly behind the RKE module. (Refer to 8 - ELEC-
TRICAL/POWER LOCKS/REMOTE KEYLESS
ENTRY MODULE - REMOVAL).
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) Turn the bulb holder counterclockwise about
sixty degrees on the cluster electronic circuit board
(Fig. 6).(4) Pull the bulb and bulb holder unit straight
back to remove it from the bulb mounting hole in the
cluster electronic circuit board.
CLUSTER LENS, HOOD, AND MASK
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) From the back of the instrument cluster,
remove the eight screws around the outer perimeter
of the rear cover that secure the lens, hood, and
mask unit to the cluster housing (Fig. 7).
(4) Remove the lens, hood, and mask unit from the
face of the instrument cluster.
ASSEMBLY
Some of the components for the instrument cluster
used in this vehicle are serviced individually. The
serviced components include the incandescent instru-
ment cluster illumination lamp bulbs (including the
integral bulb holders), and the cluster lens, hood and
mask unit. Following are the procedures for assem-
bling these components to the instrument cluster
unit.
Fig. 6 Cluster Bulb Remove/Install
1 - INSTRUMENT CLUSTER
2 - BULB & HOLDER (11)
Fig. 7 Instrument Cluster Components
1 - SCREW (9)
2 - REAR COVER
3 - CLUSTER HOUSING
4 - LENS, HOOD & MASK
DRINSTRUMENT CLUSTER 8J - 15
INSTRUMENT CLUSTER (Continued)

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.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp bulb and bulb holder units.
If the vehicle is equipped with the optional Remote
Keyless Entry (RKE) system, and the RKE receiver
module was removed from the instrument cluster
rear cover to access the lower center cluster illumi-
nation lamp, reinstall the RKE module after the bulb
is replaced on the circuit board. (Refer to 8 - ELEC-
TRICAL/POWER LOCKS/REMOTE KEYLESS
ENTRY MODULE - INSTALLATION).
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the instrument
cluster, the electronic circuit board and/or the
gauges.
(1) Insert the bulb and bulb holder unit straight
into the correct bulb mounting hole in the cluster
electronic circuit board (Fig. 6).
(2) With the bulb holder fully seated against the
cluster electronic circuit board, turn the bulb holder
clockwise about sixty degrees to lock it into place.
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
CLUSTER LENS, HOOD, AND MASK
(1) Position the cluster lens, hood, and mask unit
over the face of the instrument cluster (Fig. 7). Be
certain that the odometer/trip odometer switch but-
ton is inserted through the proper clearance holes in
the mask and the lens.
(2) From the back of the instrument cluster, install
and tighten the eight screws around the outer perim-
eter of the rear cover that secure the lens, hood, andmask unit to the cluster housing. Tighten the screws
to 1 N´m (10 in. lbs.).
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
INSTALLATION
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
(1) Position the instrument cluster to the instru-
ment panel.
(2) Reconnect the instrument panel wire harness
connectors for the cluster to the connector receptacles
on the back of the cluster housing.
(3) Position the instrument cluster into the instru-
ment panel.
(4) Install and tighten the four screws that secure
the instrument cluster to the instrument panel struc-
tural support (Fig. 5). Tighten the screws to 4 N´m
(31 in. lbs.).
(5) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(6) Reconnect the battery negative cable.
8J - 16 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

(1) Position the front fog lamp relay to the proper
receptacle in the Power Distribution Center (PDC).
(2) Align the front fog lamp relay terminals with
the terminal cavities in the PDC.
(3) Press firmly and evenly on the top of the front
fog lamp relay until the terminals are fully seated in
the PDC.
(4) Reconnect the battery negative cable.
HAZARD SWITCH
DESCRIPTION
The hazard switch is activated by a push button
located in the multifunction switch on the top of the
steering column between the steering wheel and
instrument cluster.
The hazard warning system allows the vehicle
operator to provide other vehicle operators in the
near proximity an optical indication that the vehicle
is disabled or an obstacle to traffic flow. The hazard
warning system has battery voltage at all times,
regardless of ignition position.
OPERATION
The instrument cluster monitors the multiplexed
multifunction switch operation. When the hazard
warning switch is activated, the instrument cluster
will send a J1850 bus message to the Front Control
Module (FCM), then activate the two turn signal
indicators and audible click in the instrument clus-
ter.
The FCM will then activate the necessary relays in
the Power Distribution Center (PDC) to begin flash-
ing both the front and rear turn signal indicator
lamps.
HEADLAMP
REMOVAL
(1) Disconnect and isolate the negitive battery
cable.
(2) Remove the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - REMOVAL).
(3) Seperate the socket from the headlamp unit.
INSTALLATION
CAUTION: Do Not Touch the bulb glass with fingers
or other oily surfaces. Reduced bulb life will result.
(1) Install the socket into the headlamp unit.
(2) Install the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - INSTALLATION).(3) Connect the negitive battery cable.
HEADLAMP SWITCH
DESCRIPTION
The multiplexed headlamp switch is located on the
instrument panel. The headlamp switch controls the
parking lamps, fog lamps and the headlamps. A sep-
arate switch in the module controls the interior
lamps and instrument cluster illumination. This
switch also contains a rheostat for controlling the
illumination level of the cluster lamps.
OPERATION
The multiplexed headlamp switch has an off, park-
ing lamp, fog lamp and a headlamp on position. High
beams are controlled by the multiplexed multifunc-
tion switch on the steering column. The fog lamps
are illuminated by pulling back on the headlamp
switch knob when in the parking lamp or headlamp
ON position.The headlamp switch cannot be
repaired. It must be replaced.
The Instrument Cluster monitors the headlamp
and multifunction switch operation. When the head-
lamp switch is rotated to the parking lamp or On
position the Instrument Cluster sends a J1850 mes-
sage to the Front Control Module, which is mated to
the power distribution center to become the Inte-
grated Control Module, to illuminate the appropriate
bulbs. When the multifunction switch is activated to
the optical horn or high beam position the Instru-
ment Cluster illuminates the high beam indicator
and sends a J1850 message to the Front Control
Module to illuminate the appropriate bulbs.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
8L - 14 LAMPS/LIGHTING - EXTERIORDR
FOG LAMP RELAY (Continued)