
OPERATION
The Rear Window Defogger (Fig. 1) system consists
of two vertical bus bars linked by a series of grid
lines on the inside surface of the rear window. The
electrical circuit consists of the rear defogger switch
in the HVAC control assembly and a relay with timer
switch to turn OFF the system after ten minutes.
The main feed circuit is protected by fuse 13 (40
amp) in the Power Distribution Center (PDC) which
is integrated as a unit call Integrated Power Module
(IPM). The rear defogger switch and relay also acti-
vates the heated power side view mirrors and heated
windshield wiper de-icer. The heated windshield
wiper de-icer is powered by the RUN/ACC relay in
the IPM and feed thru fuse #11 (20 amp) in the PDC.
The heated mirror circuit is protected by a non-servi-
cable Positive Temperature Coefficient (PTC) located
inside the PDC. The heated windshield wiper de-icer
circuit is protected by fuse 11 (20 amp) in the PDC.
The Heated Windshield Wiper Deicer is also acti-
vated when the DEFROST mode is selected on the
HVAC. In the DEFROST mode the rear defogger
relay/timer is bypassed, the heated windshield wiper
de-icer will stay ON until the another mode is
selected. For circuit information and component loca-
tion refer to appropriate section for Wiring Diagrams.
CAUTION:
Since grid lines can be damaged or scraped off
with sharp instruments, care should be taken in
cleaning the glass or removing foreign materials,
decals or stickers. Normal glass cleaning solvents
or hot water used with rags or toweling is recom-
mended.
DEFOGGER RELAY
DESCRIPTION
There is no heated glass relay it is integrated into
the (E.B.L) relay that is located in the IPM in the
engine compartment.
REAR WINDOW DEFOGGER
GRID
STANDARD PROCEDURE - GRID LINE
REPAIR-REAR
For Grid repair procedure for the rear window
defogger (Refer to 8 - ELECTRICAL/HEATED
GLASS/WINDSHIELD GRID - STANDARD PROCE-
DURE).
REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is integrated into
the HVAC control panel assembly (Fig. 3)
OPERATION
A LED indicator will illuminate when the switch is
activated. The switch energizes the HVAC control
assembly when it requests the Front Control Module
(FCM) to activate the rear window defogger relay.
The relay controls the current to flow to the grids of
the rear window defogger, heated power side view
mirrors and the heated windshield wiper de-icer. The
defogger relay will be on for approximately 10 min-
utes or until the control switch or ignition is turned
off.
Fig. 3 HVAC CONTROL PANEL
1 - Trim Bezel
2 - ACT Sensor
3 - A/C Request Switch
4 - Rear Window Defogger/Heated Mirrors Switch Combo
5 - Front Window Defroster Mode Selector
8G - 2 HEATED GLASSRS
HEATED GLASS (Continued)
ProCarManuals.com

WINDSHIELD GRID
DIAGNOSIS AND TESTING - SYSTEM TEST
Electrically heated rear window defogger or the
heated windshield wiper deicer operation can be
checked on the vehicle in the following manner:
(1) Turn the ignition switch to the ON position.
(2) Using a ammeter on the battery, turn the rear
defogger control switch to the ON position, a distinct
increase in amperage draw should be noted.
(3) The rear window defogger or the heated wind-
shield wiper deicer operation can be checked by feel-
ing the glass. A distinct difference in temperature
between the grid lines and adjacent clear glass can
be detected in 3 to 4 minutes of operation.
(4) Using a DC voltmeter (Fig. 4) contact terminal
B with the negative lead, and terminal A with the
positive lead. The voltmeter should read 10-14 volts.
(5) Indicator light illumination means that there is
power available at the switch only and does not nec-
essarily verify system operation.
(6) If turning the defogger switch ON, no distinct
current draw on the ammeter the problem should be
isolated in the following manner:
²Confirm that ignition switch is ON.
²Ensure that the heated rear window or the
heated windshield wiper deicer feed pigtail is con-
nected to the wiring harness and that the ground
pigtail is in fact grounded.
²Ensure that the proper fuse in the PDC is OK.
(7) When the above steps have been completed and
the system is still inoperative it may be necessary to
connect a DRBIII scan tool and refer to the Diagnos-
tic Service Manual, you may also check for the fol-
lowing being defective:
²HVAC control assembly
²Rear window defogger relay in the IPM.
²Check for loose connector or a wire pushed out
of connector.
²Rear window or the windshield grid lines (all
grid lines would have to be broken, or one of the feed
pigtails not connected to the bus bar, for no ammeter
deflection).
(8) If turning the switch ON produces severe volt-
meter deflection, the circuit should be closely checked
for a shorting condition.
(9) If the system operation has been verified but
indicator LED does not light, replace the HVAC con-
trol assembly.
(10) For detailed wiring information, refer to the
appropriate section for Wiring Diagrams.
STANDARD PROCEDURE - GRID LINE AND
TERMINAL REPAIR
WARNING:
REPAIR KIT MAY CAUSE SKIN OR EYE IRRITATION.
CONTAINS EPOXY RESIN AND AMINE TYPE HARD-
ENER, HARMFUL IF SWALLOWED. AVOID CON-
TACT WITH SKIN AND EYES. FOR SKIN, WASH
AFFECTED AREAS WITH SOAP AND WATER. DO
NOT TAKE INTERNALLY. IF TAKEN INTERNALLY,
INDUCE VOMITING; CALL A PHYSICIAN IMMEDI-
ATELY. IF IN CONTACT WITH EYES, FLUSH WITH
PLENTY OF WATER. USE WITH ADEQUATE VENTI-
LATION. DO NOT USE NEAR FIRE OR FLAME. CON-
TENTS CONTAINS 3% FLAMMABLE SOLVENTS.
KEEP OUT OF REACH OF CHILDREN.
The repair for the front windshield or the rear win-
dow grids are the same.
The repair of grid lines and replacement of the ter-
minal is possible using the MopartRepair Package
or equivalent.
(1) Clean area surrounding grid line or terminal
by gently rubbing area with steel wool.
(2) Wipe area with clean cloth soaked in alcohol or
similar solvent. It is necessary that all contaminants
be removed from repair area.
Fig. 4 Grid Line Test
1 - VOLTMETER
2 - TERMINAL B
3 - FEED WIRE
4 - MID-POINT C (TYPICAL)
5 - HEATED REAR WINDOW GRIDS
6 - GROUND WIRE
7 - TERMINAL A
RSHEATED GLASS8G-3
ProCarManuals.com

²Remote Keyless Entry Module (RKE)- Refer
toRemote Keyless Entry Modulein Power Locks
for more information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console for more information.
²Heated Seat Module (HSM)- Refer toHeated
Seat Modulein Electronic Control Modules for more
information.
²Memory Heated Seat Module (MHSM)-If
the vehicle is equipped with the Memory System,
refer toMemory Seat Mirror Module (MSMM)in
Electronic Control Modules for more information.
Refer toWiring Diagramsfor complete circuit
diagrams. Following are general descriptions of the
major components in the heated seat system.
OPERATION
The heated seat system will only operate when the
ignition switch is in the On position, and the surface
temperature at the front seat heating element sen-
sors is below the designed temperature set points of
the system. The heated seat system will not operate
in ambient temperatures greater than about 41É C
(105É F). The front seat heating elements and sensors
are hard wired to the Heated Seat Module (HSM) or
the Memory Heated Seat Module (MHSM).
The heated seat switches are hard wired to the
Body Control Module (BCM). The BCM monitors the
heated seat switch inputs, then sends heated seat
switch status messages to the HSM or MHSM over
the Programmable Communications Interface J1850
(PCI) data bus. The HSM or MHSM contains the con-
trol logic for the heated seat system. The HSM or
MHSM responds to the heated seat switch status
messages, ignition switch status messages, and the
front seat heating element sensor inputs by control-
ling the output to the front seat heating elements
through integral solid-state relays.
When a seat heater is turned on, the sensor
located on the seat cushion electric heater element
provides the HSM or MHSM with an input indicating
the surface temperature of the seat cushion. If the
surface temperature input is below the temperature
set point for the selected Low or High heated seat
switch position, the HSM or MHSM energizes the
integral solid-state relay, which supplies battery cur-
rent to the heating elements in the seat cushion and
back. When the sensor input indicates the correct
temperature set point has been achieved, the HSM or
MHSM de-energizes the solid-state relay. The HSM
or MHSM will continue to cycle the solid-state relay
as needed to maintain the temperature set point.
The HSM or MHSM and the seat heater elements
operate on non-switched battery current supplied
through the power seat fuse in the intelligent powermodule. However, the HSM or MHSM will automati-
cally turn off the heating elements if it detects an
open in the sensor circuit, a short in the heating ele-
ment circuit causing an excessive current draw, or
when the ignition switch is turned to the Off posi-
tion.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the heated seat system.
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 2). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
Fig. 2 HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)
ProCarManuals.com

OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
depressed, the Low position is selected and the high
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the low position LED indica-
tor illuminates. When the switch rocker is moved to
its neutral position (middle), Off is selected and both
LED indicators are extinguished.
Both switches provide separate resistor multi-
plexed hard wire inputs to the BCM to indicate the
selected switch position. The BCM monitors the
switch inputs and sends heated seat switch status
messages to the Heated Seat Module (HSM) or the
Memory Heated Seat Module (MHSM) over the Pro-
grammable Communications Interface (PCI) data
bus. The HSM or MHSM responds to the heated seat
switch status messages by controlling the output to
the seat heater elements of the selected seat. The
Low heat position set point is about 36É C (97É F),
and the High heat position set point is about 41É C
(105É F).
DIAGNOSIS & TESTING - HEATED SEAT
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check the fused ignition switch output (run)
fuse in the intelligent power module. If OK, go to
Step 2. If not OK, repair the shorted circuit or com-
ponent as required and replace the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) fuse in the intelligent power module. If
OK, go to Step 3. If not OK, repair the open fused
ignition switch output (run) circuit to the ignition
switch as required.
(3) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel and disconnect the instrument panel wire har-
ness connectors from the heated seat switch connec-
tor receptacle. Check for continuity between the
ground circuit cavity of the instrument panel wireharness connector for the inoperative heated seat
switch(es) and a good ground. There should be conti-
nuity. If OK, go to Step 4. If not OK, repair the open
ground circuit to ground as required.
(4) Reconnect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (run) cir-
cuit cavity of the instrument panel wire harness con-
nector for the inoperative heated seat switch(es). If
OK, turn the ignition switch to the Off position, dis-
connect and isolate the battery negative cable, and go
to Step 5. If not OK, repair the open fused ignition
switch output (run) circuit to the intelligent power
module fuse as required.
(5) Test the heated seat switch(es) as shown in the
Heated Seat Switch Test chart (Fig. 3). If OK, go to
Step 6. If not OK, replace the faulty heated seat
switch(es).
DRIVER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin4&5OPEN
Low Pin4&53570
High Pin4&51430
All resistance values are61%.
(6) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM) con-
nector receptacle. Check for continuity between the
seat heater switch sensor ground circuit cavity of the
instrument panel wire harness connector for the
Fig. 3 SWITCH CONNECTOR
RSHEATED SEAT SYSTEM8G-9
DRIVER HEATED SEAT SWITCH (Continued)
ProCarManuals.com

OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements to the current flow is released in the form
of heat. The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
HSM or MHSM supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The MSM or
MHSM uses this temperature sensor input to moni-
tor the temperature of the seat, and regulates the
current flow to the seat heating elements accordingly.
DIAGNOSIS & TESTING - HEATED SEAT
ELEMENT
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, near the rear edge of the seat cushion frame.
For circuit descriptions and diagrams, refer to Group
8W, Wiring Diagrams.
SEAT CUSHION
(1) Disconnect and isolate the battery negative
cable. Unplug the 4-way heated seat cushion wire
harness connector.
(2) Check for continuity between the two heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor. There should be continuity. If OK, go to Step 3. If
not OK, replace the faulty seat cushion cover.
(3) Check for continuity between one of the heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor and the seat cushion frame. There should be no
continuity. If OK, go to the Seat Back test. If not OK,
replace the faulty seat cushion cover.
SEAT BACK
(1) Disconnect and isolate the battery negative
cable. Unplug the 2-way heated seat back wire har-
ness connector.
(2) Check for continuity between the heated seat
driver circuit cavity and the ground circuit cavity of
the seat back cover half of the heated seat back wire
harness connector. There should be continuity. If OK,
go to Step 3. If not OK, replace the faulty seat back
cover.
(3) Check for continuity between the heated seat
driver circuit cavity of the seat back cover half of the
heated seat back wire harness connector and the seat
back frame. There should be no continuity. If OK,
test the heated seat sensor as described in this
group. If not OK, replace the faulty seat back cover.
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, and is inte-
grated into the seat cushion heating element.
DIAGNOSIS & TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat cushion ele-
ment wire harness connector from the power seat
wire harness. The power seat wire harness connec-
tors for the seat cushion and seat back heating ele-
ments are secured to a bracket located under the
rear edge of the seat cushion frame.
(2) Using an ohmmeter, check the resistance
between the seat sensor circuit and the seat temper-
ature sensor input circuit cavities of the 4-way
heated seat cushion element wire harness connector.
The sensor resistance should be between 2 kilohms
at 15É C (60É F) and 200 kilohms at 30É C (85É F). If
not OK, replace the faulty seat cushion cover trim
and sensor unit.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 5). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT ELEMENT (Continued)
ProCarManuals.com

depressed, the Low position is selected and the high
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the low position LED indica-
tor illuminates. When the switch rocker is moved to
its neutral position (middle), Off is selected and both
LED indicators are extinguished.
Both switches provide separate resistor multi-
plexed hard wire inputs to the BCM to indicate the
selected switch position. The BCM monitors the
switch inputs and sends heated seat switch status
messages to the Heated Seat Module (HSM) or the
Memory Heated Seat Module (MHSM) over the Pro-
grammable Communications Interface (PCI) data
bus. The HSM or MHSM responds to the heated seat
switch status messages by controlling the output to
the seat heater elements of the selected seat. The
Low heat position set point is about 36É C (97É F),
and the High heat position set point is about 41É C
(105É F).
DIAGNOSIS & TESTING - HEATED SEAT
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check the fused ignition switch output (run)
fuse in the intelligent power module. If OK, go to
Step 2. If not OK, repair the shorted circuit or com-
ponent as required and replace the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) fuse in the intelligent power module. If
OK, go to Step 3. If not OK, repair the open fused
ignition switch output (run) circuit to the ignition
switch as required.
(3) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel and disconnect the instrument panel wire har-
ness connectors from the heated seat switch connec-
tor receptacle. Check for continuity between the
ground circuit cavity of the instrument panel wire
harness connector for the inoperative heated seat
switch(es) and a good ground. There should be conti-
nuity. If OK, go to Step 4. If not OK, repair the open
ground circuit to ground as required.
(4) Reconnect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (run) cir-
cuit cavity of the instrument panel wire harness con-
nector for the inoperative heated seat switch(es). If
OK, turn the ignition switch to the Off position, dis-
connect and isolate the battery negative cable, and go
to Step 5. If not OK, repair the open fused ignition
switch output (run) circuit to the intelligent power
module fuse as required.
(5) Test the heated seat switch(es) as shown in the
Heated Seat Switch Test chart (Fig. 6). If OK, go to
Step 6. If not OK, replace the faulty heated seat
switch(es).
PASSENGER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin3&4OPEN
Low Pin3&43570
High Pin3&41430
All resistance values are61%.
(6) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM) con-
nector receptacle. Check for continuity between the
seat heater switch sensor ground circuit cavity of the
instrument panel wire harness connector for the
inoperative heated seat switch(es) and a good ground.
There should be no continuity. If OK, go to Step 7. If
not OK, repair the shorted seat heater switch sensor
ground circuit as required.
Fig. 5 HEATED SEAT SWITCHES
8G - 12 HEATED SEAT SYSTEMRS
PASSENGER HEATED SEAT SWITCH (Continued)
ProCarManuals.com

HORN
TABLE OF CONTENTS
page page
HORN
DESCRIPTION............................1
OPERATION.............................1
DIAGNOSIS AND TESTING..................1
HORN
DIAGNOSIS AND TESTING..................3
REMOVAL...............................4INSTALLATION............................5
HORN RELAY
DIAGNOSIS AND TESTING..................5
REMOVAL...............................5
INSTALLATION............................5
HORN SWITCH
DESCRIPTION............................5
HORN
DESCRIPTION
HORN SYSTEM
WARNING:
ON VEHICLES EQUIPPED WITH AIRBAG, REFER TO
ELECTRICAL, RESTRAINTS FOR SAFETY PRECAU-
TIONS. DISCONNECT THE NEGATIVE CABLE FROM
THE BATTERY BEFORE SERVICING COMPONENTS
INVOLVING THE AIRBAG SYSTEM. ACCIDENTAL
DEPLOYMENT OF AIRBAG AND PERSONAL INJURY
CAN RESULT.
The horn circuit consists of a horn switch, clock-
spring, horn relay, horns and intelligent power mod-
ule. The horn switch is a membrane switch located in
the airbag trim cover. The horns are located forward
of the left front wheel behind the bumper fascia.
OPERATION
The horn relay plugs into the intelligent power
module which is located in the engine compartment.
For circuit information and component locations,
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 horns will not function if the switch is
ªCLOSEDº for more than 30 seconds. Once the
switch is ªOPENº, a 20±30 second delay will occur
before the horns are functional again.
DIAGNOSIS AND TESTING
Refer to Horn System Test below. If the horn does
not sound, check horn fuse located in the intelligent
power module. If the fuse is blown, replace with the
correct fuse. If the horns fail to sound and the new
fuse blows when depressing the horn switch, a short
circuit in the horn or the horn wiring between the
fuse terminal and the horn is responsible, or a defec-
tive horn switch allowed the horn to burn out is
responsible.
If the fuse is OK, test horn relay (Refer to 8 -
ELECTRICAL/HORN/HORN RELAY - DIAGNOSIS
AND TESTING).
If the relay is OK, test horn. Refer to Horn System
Test.
CAUTION:
Continuous sounding of horn may cause horn relay
to fail.
Should the horn sound continuously:
²Unplug the horn relay from intelligent power
module.
²Refer to (Refer to 8 - ELECTRICAL/HORN/
HORN RELAY - DIAGNOSIS AND TESTING).
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.
RSHORN8H-1
ProCarManuals.com

CONDITION POSSIBLE CAUSE CORRECTION
FUSE BLOWS WHEN HORN
SOUNDS(1) SHORT CIRCUIT IN HORN OR
HORN WIRING.(1) REMOVE HORN RELAY,
CHECK FOR SHORTED HORN OR
HORN WIRING. DISCONNECT
HORN WIRE HARNESS TO
ISOLATE SHORT AND REPAIR AS
NECESSARY.
(2) FAULTY CLOCKSPRING. (2) REPLACE CLOCKSPRING.
FUSE BLOWS WITHOUT
BLOWING HORN(1) SHORT CIRCUIT. (1) REMOVE RELAY, INSTALL
NEW FUSE, IF FUSE DOES NOT
BLOW REPLACE HORN RELAY. IF
FUSE BLOWS WITH RELAY
REMOVED, CHECK FOR SHORT
TO GROUND WITH OHMMETER
ON CIRCUIT BETWEEN
TERMINALS 30 & 86 AND THE
FUSE TERMINAL. REPAIR AS
NECESSARY.
(2) FAULTY CLOCKSPRING. (2) REPLACE CLOCKSPRING.
HORN
DIAGNOSIS AND TESTING
HORN
(1) Disconnect wire connector at horn.
(2) Using a voltmeter, connect one lead to ground
terminal and the other lead to the positive wire ter-
minal (Fig. 1).
(3) Depress the horn switch, battery voltage
should be present.
(4) If no voltage, refer toHORNS WILL NOT
SOUND. If voltage is OK, go to step Step 5.
(5) Using ohmmeter, test ground wire for continu-
ity to ground.
(6) If no ground repair as necessary.
(7) If wires test OK and horn does not sound,
replace horn.
HORNS SOUND CONTINUOUSLY
CAUTION:
Continuous sounding of horns may cause relay to
fail.
The horn switch (membrane) sometimes can be the
cause without the switch being depressed.
(1) Remove the horn relay from the intelligent
power module.
(2) Using a continuity tester, test continuity from
the X3 cavity of the horn relay to ground. Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harnessrouting and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
(a) If continuity is detected, proceed to step Step
3.
(b) If NO continuity, replace the horn relay.
(3) Remove the airbag trim cover from the steering
wheel and disengage horn connector.
(4) Install horn relay into intelligent power mod-
ule.
(a) If horn does not sound, replace airbag trim
cover.
(b) If horn sounds, repair grounded X3 circuit
from intelligent power module to clockspring in the
steering column. Refer to the appropriate wiring
information. The wiring information includes wir-
ing diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and loca-
tion views for the various wire harness connectors,
splices and grounds.HORNS WILL NOT SOUND
Check horn fuse#8intheintelligent power mod-
ule. If fuse is blown, check for a shorted switch in the
airbag module. and refer to FUSE BLOWN section. If
fuse is OK, refer to FUSE OK section.
FUSE BLOWN
(1) Verify condition of battery terminals and volt-
age, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
- DIAGNOSIS AND TESTING). If battery connec-
tions and battery charge is OK proceed to Step 2.
RSHORN8H-3
HORN (Continued)
ProCarManuals.com