diagram JEEP CHEROKEE 1994 Service User Guide

HORNS
²Disconnect horn connector. Depress horn switch.
There should be 12 volts at the horn connector. If
not, repair open to relay.
²Measure the resistance between the horn bracket
and chassis ground. The meter should read zero
ohms. If not, check mounting screw for corrosion and
replace as necessary.
²If above steps do not identify a problem, replace
horns.
YJ
Wrangler/YJ horns are located on the drivers side
inner fender.
REPLACEMENT
(1) Disconnect wire harness connector from the
horn (Fig. 3).
(2) Remove horn and bracket mounting bolt. Horn
and bracket are removed as an assembly.
(3) To install, reverse the removal procedures.
DIAGNOSIS AND REPAIR
Refer to Group 8W - Wiring Diagrams for a com-
plete circuit diagram.
HORN RELAY
²Inspect 10 amp fuse, #F15, located in the power
distribution center (PDC). Replace fuse as required.
²Depress horn switch. The relay contacts should
click. If OK, go to HORN. If not, go to next step.
²Remove relay from PDC. There should be 12 volts
at cavities 2 and 5. If not, repair open in circuit to
relay.
²Depress horn switch. Measure resistance between
relay cavity 1 and ground. The meter should read
zero ohms. If not, repair open to horn switch ground.
²Measure resistance between relay cavity 4 and
ground. The meter should read almost zero ohms
(horn resistance) If OK, replace relay. If not, repair
open in circuit between relay and horn.
HORN
²Disconnect horn connector. Depress horn switch.
There should be 12 volts at the horn connector pin A.
If not, repair open to relay.
²Measure the resistance between the horn connec-
tor pin B and chassis ground. The meter should read
zero ohms. If not, repair open to ground.
²If above steps do not identify a problem, replace
horn.
Fig. 2 Horn Relay
Fig. 3 Horn Removal/InstallationÐYJ
8G - 2 HORNSJ

TEST PROCEDURES
INDEX
page page
Checking for Diagnostic Trouble Code......... 5
Electrical Tests at Powertrain Control Module.... 6
Electrical Tests at Servo.................... 5
Inoperative System........................ 5
Operational Check (Road Test)............... 7
Road Test............................... 5Speed Control Switch (Turn Signal Lever) Test . . . 7
Stop Lamp Speed Control Switch Test......... 7
Vacuum Supply Test....................... 7
Vehicle Speed Control System Electrical Tests . . . 5
Vehicle Speed Sensor Test.................. 5
ROAD TEST
Refer to Operational Check (Road Test) section to
verify reports of speed control system malfunction.
INOPERATIVE SYSTEM
Road test vehicle to verify reports of speed control
system malfunction. An inspection should be made
for loose electrical and vacuum connections at the
servo.
Check for correct installation of the vacuum check
valve in the hose from servo to vacuum source. The
word VAC on the valve must point toward the vac-
uum source.
Corrosion should be removed from electrical termi-
nals and a light coating of Mopar MultiPurpose
Grease, or equivalent, applied.
Inspection also should be made to verify that both
ends of the speed control cable are securely attached.
CHECKING FOR DIAGNOSTIC TROUBLE CODE
(1) When trying to verify a speed control system
electronic malfunction use a DRB scan tool to find
the cause (refer to Powertrain Diagnostic Procedures
manual).
If DRB is not available, the Diagnostic Trouble
Code (DTC) may be determined with the following
method:
(a) With key inserted in ignition switch, cycle
switch to ON position 3 times. On third cycle, leave
switch in ON position.
(b) After switch has been cycled 3 times, observe
Malfunction Indicator Lamp (CHECK ENGINE)
on instrument cluster. If a DTC is present, the code
will be displayed in a series of flashes representing
digits. Three flashes in rapid succession, a slight
pause, then 4 flashes in rapid succession would in-
dicate DTC 34.
(2) If a DTC 34 is observed, perform tests in the
sections Electrical Tests at Servo and Electrical Tests
at Powertrain Control Module.
If a DTC 15 is observed, perform test for a faulty
vehicle speed sensor.
(3) Correct any problems found when performing
these tests and recheck for DTC if changes were
made.
VEHICLE SPEED SENSOR TEST
For testing of the vehicle speed sensor and related
components, refer to Powertrain Diagnostic Proce-
dures manual.
VEHICLE SPEED CONTROL SYSTEM ELECTRICAL
TESTS
Vehicle speed control systems may be tested using
two different methods. One involves use of a DRB
scan tool. If this test method is desired, refer to Pow-
ertrain Diagnostic Procedures manual.
The other test method uses a voltmeter. The volt-
meter method is described in the following tests.
If any information is needed concerning wiring, re-
fer to Section 8W - Wiring Diagrams.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals, or seals. If
these components are damaged, intermittent or
complete system failure may occur.
ELECTRICAL TESTS AT SERVO
(1) Turn ignition switch to the ON position. With
speed control switch in the ON position, setup a volt-
meter to read battery voltage and connect negative
lead to a good chassis ground.
(2) Disconnect 4-way connector going to servo
(Figs. 2 and 3). Blue wire with red tracer of main
harness 4-way connector should read approximately
battery voltage. If not, check for loose connections,
brake switch adjustment or, repair main harness as
necessary.
(3) Connect a jumper wire between male and fe-
male terminals of blue wire with red tracer. The
other 3 male terminals from servo should show bat-
tery voltage. If not, replace servo.
(4) Using an ohmmeter, connect one lead to a good
body ground. Touch other lead to black wire terminal
in 4-way connector of main harness. Meter should
show continuity. If not, repair ground circuit as nec-
essary.
JVEHICLE SPEED CONTROL SYSTEM 8H - 5

TURN SIGNALS AND HAZARD WARNING FLASHER
CONTENTS
page page
HAZARD LAMPSÐXJ.................... 1
HAZARD LAMPSÐYJ.................... 2
TURN SIGNALSÐXJ..................... 1TURN SIGNALSÐYJ..................... 2
TURN/HAZARD SWITCH REPLACEMENT - ALL
MODELS............................. 3
TURN SIGNALSÐXJ
Refer to Section 8W - Wiring Diagrams for cir-
cuit wiring diagram.
DESCRIPTION
With the turn signal lever in its up or down posi-
tion and the ignition switch in ACCESSORY or ON,
current flows through the:
²turn/hazard switch
²selected turn indicator bulb
²front and rear turn signal bulbs
²and the front side marker bulb.
With the headlamps OFF, the turn and front side
marker lamps flash in unison.With the headlamps
ON, the turn and front side marker lamps flash al-
ternately.
DIAGNOSISÐTURN SIGNAL INOPERATIVE
(1) A turn signal indicator that does not flash usu-
ally indicates a burned out turn signal bulb. Check
for and replace if defective. System should now func-
tion properly. If not, go to next step.
High generator output voltage can burn out
lamps rapidly.(2) Remove and inspect 20 amp #8 fuse. Replace if
necessary. If OK, go to next step.
(3) Remove turn flasher, light blue can, located in
upper left corner of fuse block.
(4) Turn ignition switch to ACCESSORY. Check
for battery voltage at flasher bottom cavity on fuse
block. If OK, go to next step. If not, repair open cir-
cuit in wiring between turn flasher and #8 fuse.
(5) Turn ignition switch to ACCESSORY. Move
turn signal lever up or down. Replace turn flasher
with known good flasher. The lamps should flash. If
not, replace original flasher and go to next step.
(6) Turn ignition switch to OFF. Follow procedure
for turn/hazard switch replacement to locate steering
column connector. Unplug connector.
(7) Turn ignition switch to ACCESSORY. Check
for battery voltage at connector terminal L. If OK,
replace turn/hazard switch and check that lamps
flash. If not, repair open circuit in wiring between
turn flasher and steering column connector terminal
L.
HAZARD LAMPSÐXJ
Refer to Section 8W - Wiring Diagrams for cir-
cuit wiring diagram.
DESCRIPTION
With the hazard switch ON, current flows through
the:
²hazard flasher
²the turn/hazard switch
²two front turn signal bulbs
²two rear turn signal bulbs
²two front side marker bulbs
²and two turn indicator bulbs.
All of these bulbs will flash on and off.
DIAGNOSISÐHAZARD LAMPS INOPERATIVE
(1) Inspect 20 amp #F13 fuse in Power Distribu-
tion Center (PDC). The PDC is located in the engine
compartment, passenger side. For location of fuse,check underside of PDC cover. Replace if necessary.
If OK, go to next step.
(2) Remove hazard flasher (tin can) located in fuse
block.
(3) Check for battery voltage at the terminal on
the right (3 o'clock). If OK, go to next step. If not, re-
pair open circuit in wiring between #F13 fuse and
hazard flasher right terminal.
(4) Replace hazard flasher with known good
flasher. Activate hazard warning switch. Lamps
should flash. If not, replace original flasher and go to
next step.
(5) Follow procedure for turn/hazard switch re-
placement to locate steering column connector. Un-
plug connector.
(6) Check for battery voltage at connector terminal
K. If OK, replace turn/hazard switch. If not, repair
open circuit in wiring between hazard flasher and
steering column connector terminal K.
JTURN SIGNALS AND HAZARD WARNING FLASHER 8J - 1

TURN SIGNALSÐYJ
Refer to Section 8W - Wiring Diagrams for cir-
cuit wiring diagram.
DESCRIPTION
With the turn signal lever in its up or down posi-
tion and the ignition switch in ACCESSORY or ON,
current flows through the:
²turn/hazard switch
²selected turn indicator bulb
²front and rear turn signal bulbs
²front side marker bulb
With the headlamps OFF, the turn and side
marker lamps flash in unison.With the headlamps
ON, the turn and side marker lamps flash alter-
nately.
DIAGNOSINGÐTURN SIGNAL INOPERATIVE
(1) A turn signal indicator that does not flash usu-
ally indicates a burned out turn signal bulb. Check
for and replace if defective. System should now func-
tion properly. If not, go to next step.
High generator output voltage can burn out
lamps rapidly.
(2) Locate fuse block under driver's side of instru-
ment panel.(3) Remove and inspect 15 amp #4 fuse. Replace if
necessary. If OK, go to next step.
(4) Remove turn flasher, light blue can, located in
fuse block.
(5) Turn ignition switch to ACCESSORY. Check
for battery voltage at cavity on left (closest to hazard
flasher can). If OK, go to next step. If not, repair
open circuit in wiring between turn flasher and #4
fuse.
(6) Turn ignition switch to ACCESSORY. Move
turn signal lever up or down. Replace turn flasher
with known good flasher. The lamps should flash. If
not, replace original flasher and go to next step.
(7) Turn ignition switch to OFF. Follow procedure
for turn/hazard switch replacement to locate steering
column connector. Unplug connector.
(8) Turn ignition switch to ACCESSORY. Check
for battery voltage at connector terminal L. If OK,
replace turn/hazard switch. If not, repair open circuit
in wiring between turn flasher and steering column
connector terminal L.
HAZARD LAMPSÐYJ
Refer to Section 8W - Wiring Diagrams for cir-
cuit wiring diagram.
DESCRIPTION
With the hazard switch ON, current flows through
the:
²hazard flasher
²turn/hazard switch
²two front turn signal bulbs
²two rear turn signal bulbs
²two front side marker bulbs
²two turn indicator bulbs.
All of these bulbs will flash on and off.
DIAGNOSISÐHAZARD LAMPS INOPERATIVE
(1) Inspect 20 amp #F5 fuse in Power Distribution
Center (PDC). The PDC is located in the engine com-
partment, passenger side. For location of fuse, check
underside of PDC cover. Replace if necessary. If OK,
go to next step.(2) Remove hazard flasher (tin can) located in fuse
block.
(3) Check for battery voltage at the terminal on
the left. If OK, go to next step. If not, repair open cir-
cuit in wiring between #F5 fuse and hazard flasher
left terminal.
(4) Replace hazard flasher with known good
flasher. Activate hazard warning switch. Lamps
should flash. If not, replace original flasher and go to
next step.
(5) Follow procedure for turn/hazard switch re-
placement to locate steering column connector. Un-
plug connector.
(6) Check for battery voltage at connector terminal
K. If OK, replace turn/hazard switch. If not, repair
open circuit in wiring between hazard flasher and
steering column connector terminal K.
8J - 2 TURN SIGNALS AND HAZARD WARNING FLASHERJ

CAUTION: DO NOT move the wiper switch to DE-
LAY with the intermittent wiper module removed
from the circuit. If the switch is moved to the DE-
LAY position during the next step, the switch will
be damaged.
²Test wiper operation in LOW and HIGH speed
modes, and test washer operation. If these modes
were inoperative, but are OK now, replace failed in-
termittent wiper module.
(4) To test the wiper/washer switch, see Wiper
Switch Testing. Turn ignition switch to OFF. Posi-
tion the wiper switch as indicated, and back probe
switch side of wiper switch connector. If switch tests
OK, go to step 5. If not, replace switch and go to step
6.
(5) To further test the wiper/washer switch, turn
ignition switch to ACCESSORY or ON. Position the
wiper switch as indicated in the tests below, and
back probe switch side of wiper switch connector.
²Measure voltage at terminal E with wiper switch
in LOW, MIST and with washer switch depressed.
Meter should read battery voltage. If not, replace
switch.
²Measure voltage at connector terminal C with
wiper switch in HIGH. Meter should read battery
voltage. If not, replace switch.
²With wiper switch in LOW or HIGH, measure
voltage at connector terminal F, then move wiper
switch to OFF. Meter shold read battery voltage un-
til wipers park and then zero volts. If OK, go to step
6. If not, check wiring to wiper motor, then go to step
6.
(6) To test the wiper motor, turn the ignition
switch to ACCESSORY or ON. Position the wiper
switch and back probe the motor connector as indi-
cated.
²Wiper switch in any position, measure voltage at
terminal B. Meter should read battery voltage. If not,
repair wiring from circuit breaker.
²Wiper switch in LOW, measure voltage at termi-
nal A. Meter should read battery voltage. If OK, but
wipers do not operate, replace failed wiper motor. If
not, repair wiring from switch or intermittent wiper
module connector.
²Wiper switch in HIGH, measure voltage at termi-
nal H. Meter should read battery voltage. If OK, but
wipers do not operate, replace failed wiper motor. If
not, repair wiring from switch or intermittent wiper
module connector.
²Wiper switch in LOW or HIGH, voltmeter con-
nected to terminal D. Turn wiper switch to OFF and
observe meter. Meter should read battery voltage
when switch goes to OFF, then zero volts after wip-
ers park. If battery voltage is present, but wipers fail
to park; or, if no battery voltage present, replace
failed wiper motor.DIAGNOSING NON-INTERMITTENT WINDSHIELD
WASHER
Refer to Group 8W - Wiring Diagrams.
(1) Measure resistance from washer pump connec-
tor terminal B to a clean chassis ground. Meter
should read zero ohms. If not, repair open between
terminal B and ground.
(2) Turn ignition switch to ON and press washer
switch.
²Measure voltage at switch connector terminal B.
Meter should read battery voltage. If not, replace
wiper/washer switch.
²Measure voltage at washer pump connector termi-
nal A. Meter should read battery voltage. If OK, re-
place pump. If not, repair open between switch
connector and pump connector.
DIAGNOSING INTERMITTENT WINDSHIELD
WASHER
Refer to Group 8W - Wiring Diagrams.
(1) Measure resistance from washer pump connec-
tor terminal B to a clean chassis ground. Meter
should read zero ohms. If not, repair open between
terminal B and ground.
(2) Turn ignition switch to ON and rotate washer
switch tab forward.
²Measure voltage at wiper/washer switch connector
terminal B located at intermittent wipe module.
Meter should read battery voltage. If not, replace
wiper switch.
²Measure voltage at intermittent wipe module con-
nector terminal B (to washer pump). Meter should
read battery voltage. If not, replace intermittent
wipe module.
²Measure voltage at washer pump connector termi-
nal A. Meter should read battery voltage. If OK, re-
place pump. If not, repair open from intermittent
wipe module connector terminal B.
REAR WIPER ARM REPLACEMENT
(1) Install wiper arm remover, Snap On A192 or
equivalent, on wiper arm (Fig. 11). Lift arm and then
remove from pivot shaft.
CAUTION: Do not use a screwdriver or other prying
tool to remove an arm. This may distort it in a way
that will allow it to come off the pivot shaft in the
future, despite how carefully it is installed. NEVER
push or bend the spring clip in the base of the arm
in an attempt to release the arm. This clip is self re-
leasing.
(2) To install, reverse the removal procedure.
(3) Wet the window and check the park position by
operating the wiper motor several times.
8K - 12 WINDSHIELD WIPERSJ

DIAGNOSING REAR WIPER/WASHER
Refer to Group 8W - Wiring Diagrams.
(1) Turn ignition switch to ON and rear wiper/
washer switch to WASH.
²Measure voltage at switch connector terminal P.
Meter should read battery voltage. If not, check 20
amp, fuse #1.
²Measure voltage at switch connector terminal B.
Meter should read battery voltage. If not, replace
switch.
²Measure voltage at switch connector terminal A.
Meter should read battery voltage. If not, replace
switch.
(2) Turn ignition switch to ON and unplug rear
washer pump connector.
²Measure resistance at pump connector black wire
to ground. Meter should read zero ohms (ignition
OFF). If not, repair open to ground.
²Measure voltage at pump connector brown/white
wire, switch in WASH. Meter should read battery
voltage. If OK, replace pump. If not, check wiring.
(3) Turn ignition switch to ON, unplug rear wiper
motor connector and place wiper switch in WIPE.
²Measure resistance at motor connector terminal B
to ground. Meter should read zero ohms. If not, re-
pair open to ground.
²Measure voltage at motor connector terminal A.
Meter should read battery voltage. If not, check wir-
ing to fuse.
²Measure voltage at motor connector terminal C.
Meter should read battery voltage. If OK, replace
motor. If not, repair open to switch.
REAR WIPER/WASHER SWITCH TESTING
Fig. 15 Rear Wiper Motor
8K - 14 WINDSHIELD WIPERSJ

(7) Measure the resistance from the dimmer switch
wire harness connector terminal 1 to vehicle body
ground. The ohmmeter should indicate zero ohms. If
OK, continue with the next step. If not OK, repair
the short circuit in the wire harness that leads to
terminal 1.
(8) Measure the resistance from the dimmer switch
wire harness connector terminal 3 to vehicle body
ground. The ohmmeter should indicate zero ohms. If
OK, test the dimmer switch. Replace, if defective.
Connect the wire harness connector to the dimmer
switch. If not defective, repair the short circuit in the
wire harness that leads to terminal 3.
LOW OR HIGH BEAM INOPERATIVE BOTH
HEADLAMPS
(1) Place the headlamp switch in the OFF position.
Disconnect the dimmer switch wire harness connec-
tor.
(2) Measure the resistance from the dimmer switch
connector terminal 1 to body ground. The ohmmeter
should indicate zero ohms. If not OK, repair the open
circuit in the wire harness that leads to the head-
lamp bulbs.
(3) Measure the resistance from the dimmer switch
connector terminal 3 to vehicle body ground. The
ohmmeter should indicate zero ohms. If OK, replace
the dimmer switch. If not OK, repair the open circuit
in the wire harness that leads to headlamp bulbs.
HEADLAMP TROUBLE DIAGNOSISÐYJ VEHICLES
(1) Place the headlamp switch in the ON position.
(2) Place the headlamp dimmer switch in the
HIGH or LOW position.
(3) Disconnect the wire harness connectors from
the headlamp bulbs.
(4) If applicable, measure voltage between each
headlamp bulb wire connector terminal B and vehi-
cle body ground. The voltmeter should indicate bat-
tery voltage. If not OK, repair the open circuit in
wire harness between connector and dimmer switch.
(5) If applicable, measure the voltage between each
headlamp bulb connector terminal C and body
ground. The voltmeter should indicate battery volt-
age. If not OK, repair the open circuit in the wire
harness between the connector and the dimmer
switch.
(6) Measure the resistance from each headlamp
bulb connector terminal A to body ground. The ohm-
meter should indicate zero ohms. If not OK, repair
the open circuit in the wire harness between the con-
nectors and vehicle body ground.
SWITCH TESTS
HEADLAMPÐALL VEHICLES
(1) Refer to the applicable wiring diagram for ter-
minal reference.(2) Place the headlamp switch in the ON position.
(3) Measure the voltage between the headlamp
switch connector voltage supply terminal and vehicle
body ground. The voltmeter should indicate battery
voltage. If not OK, repair the open circuit in the wire
harness between the fuse and the switch connector
terminal.
(4) Measure the voltage between the headlamp
switch connector battery voltage OUT terminal and
vehicle body ground. The voltmeter should indicate
battery voltage. If not OK, replace the headlamp
switch.
DIMMER SWITCHÐALL VEHICLES
(1) Place the headlamp switch in the ON position.
Place the dimmer switch in the HIGH or LOW beam
position, as applicable.
(2) Measure the voltage between the dimmer
switch connector voltage supply terminal and vehicle
body ground. The voltmeter should indicate battery
voltage. If not OK, repair the open circuit in the wire
harness between the headlamp switch and the dim-
mer switch.
(3) Place the dimmer switch in the LOW beam po-
sition. Measure the voltage between the dimmer
switch connector low beam voltage OUT terminal
and body ground. The voltmeter should indicate bat-
tery voltage. If not OK, replace the dimmer switch.
(4) Place the dimmer switch in the HIGH beam po-
sition. Measure the voltage between the dimmer
switch connector high beam voltage OUT terminal
and body ground. Voltmeter should indicate battery
voltage. If not OK, replace dimmer switch.
Fig. 1 Headlamp Dimmer Switch Terminals
8L - 2 LAMPSJ

A voltage drop of one-half the full amount, approx-
imately 6 volts, indicates a good grid or closed cir-
cuit.
A voltage drop of 12 volts at the centerline indi-
cates a break in the grid between the positive volt-
meter lead and the ground.
No voltage drop (0 volts) at the centerline indicates
a break in the grid between the centerline and the
voltage source or lead.
The exact location of the break can be pinpointed
by moving positive voltmeter lead to the left or right
along grid. An abrupt change in the voltage reading
will be noticed. The break is at that point in the
grid.
REAR WINDOW DEFOGGER GRID REPAIR
Locate the broken or open grid.
Use the grid repair kit (available as a service part)
by using the following procedure:
(1) Mark the location of the broken or open grid on
the exterior surface of the glass using a suitable
marking pencil.
(2) Lightly rub the area to be repaired (inside the
rear window) using fine steel wool. Clean the area
with alcohol.
(3) Attach two strips of masking tape to the inside
surface of the rear window (above and below the
break in the grid) (Fig. 1).
(4) Remove package separator clamp and mix plas-
tic conductive epoxy thoroughly. Fold in half and cut
center corner to dispense epoxy.
(5) Apply conductive epoxy through slit in mask-
ing tape. Overlap both ends of the break.
(6) For a terminal or pigtail replacement, mask ad-
jacent areas so epoxy can be extended onto line and
buss bar. Apply a thin layer of epoxy to area where
terminal was fastened and to adjacent line.
(7) Apply a thin layer of conductive epoxy on ter-
minal and place terminal on desired location. To pre-
vent terminal from moving while the epoxy is curing,
it must be wedged or clamped.
(8) Carefully remove masking tape from grid line.
(9) Allow epoxy to cure 24 hours at room tempera-ture or use heat gun with a 260É-371ÉC (500É-700ÉF)
range for 15 minutes. Hold gun approximately
254mm (10 inches) from repaired area.
(10) After conductive epoxy is properly cured re-
move wedge from terminal and check out operation
of rear window defogger. Do not attach connectors
until curing is complete.
WARNING: REPAIR KIT MAY CAUSE SKIN OR EYE
IRRITATION.
CONTAINS EPOXY RESIN AND AMINE TYPE
HARDENER, HARMFUL IF SWALLOWED. AVOID
CONTACT WITH SKIN AND EYES. FOR SKIN,
WASH AFFECTED AREAS WITH SOAP AND WA-
TER. DO NOT TAKE INTERNALLY. IF TAKEN
INTERNALLY, INDUCE VOMITING; CALL A
PHYSICIAN IMMEDIATELY. IF IN CONTACT
WITH EYES, FLUSH WITH PLENTY OF WATER.
USE WITH ADEQUATE VENTILATION. DO NOT
USE NEAR FIRE OR FLAME. CONTENTS CON-
TAIN 3% FLAMMABLE SOLVENTS.
WARNING: KEEP OUT OF REACH OF CHIL-
DREN.
SWITCH TESTING
DIAGNOSIS
Refer to Group 8W - Wiring Diagrams for a com-
plete circuit diagram.
BATTERY, IGNITION & FUSES
²Check fuses #6 and #9 (YJ), or #8 and #18 fuse
(XJ). Replace as required.
²If the fuses are not blown check the battery side of
#18 fuse (XJ) or fuse #6 (YJ) for battery voltage. If
battery voltage is not present replace the Maxi fuse
located in the power distribution center.
²Check the ignition side of fuse #9 (YJ), fuse #8
(XJ) for battery voltage. If battery voltage is not
present check for an open from the ignition switch.
DEFOGGER SWITCH
Defogger switch connector separated from de-
fogger switch; turn ignition switch to ON for
voltage tests; turn ignition switch to OFF for re-
sistance tests
²Measure voltage at defogger switch connector ter-
minal D. The meter should read approximately 5
volts momentarily. If not, repair open from relay.
²Refer to switch diagram for resistance tests. If val-
ues do not match, replace defogger switch.
DEFOGGER RELAY
Defogger relay connector separated from de-
fogger relay; turn ignition switch to ON for volt-
age tests; turn ignition switch to OFF for
resistance tests
Fig. 1 Grid Line Repair (Typical)
8N - 2 REAR WINDOW DEFOGGERJ

²Measure voltage at relay connector terminal 4.
The meter should read battery voltage. If not, repair
open to fuse #18 (XJ), or fuse #9 (YJ).
²Measure voltage at relay connector terminal 5.
The meter should read battery voltage. If not, repair
open from #8 fuse XJ, or fuse #6 YJ.
²Measure resistance between relay connector termi-
nal 1 and left side (driver's side) of defogger grid.
The meter should read zero ohms. If not, repair open
between relay connector and left side of defogger
grid.
²Measure resistance between relay connector termi-
nal 2 and a clean chassis ground. The meter should
read zero ohms. If not, repair open between relay
connector and ground.
²Connect relay connector and measure voltage at
terminal 3. The meter should read approximately 5volts. If not, replace defogger relay.
INDICATOR LAMP
Refer to switch diagram for resistance tests. If val-
ues do not match, replace defogger switch.
DEFOGGER GRID
Turn defogger switch to ON; turn ignition
switch to ON for voltage tests; turn ignition
switch to OFF for resistance tests
²Measure voltage at left side (driver's side) of defog-
ger grid. The meter should read battery voltage. If
not, repair open from defogger relay.
²Measure resistance for right side of defogger grid
to a clean chassis ground. The meter should read
zero ohms. If not, repair open between right side of
defogger grid and ground.
JREAR WINDOW DEFOGGER 8N - 3

code received matches the code in the receiver memory
circuit, the receiver triggers the door lock/unlock relays.
The relays complete the circuit to the electric door lock
solenoid to either lock or unlock the doors.
SYSTEM OPERATION
To activate the system, aim the transmitter diode
toward the receiver and press the transmitter signal
button to lock or unlock the doors as desired.
Effective transmitter range is 4.75 meters (15 ft.)
with the transmitter positioned no more than 45 de-
grees from the receiver centerline.
For complete circuit diagrams refer to Group
8W - Wiring Diagrams.
TRANSMITTER PROGRAMMING
Up to 4 Transmitter Identification Codes (TIC's) can
be programed into the receiver at any given time.
(1) Open the driver's door of the vehicle. Leave it
open through the programming procedure.
(2) Move the mechanical door lock lever to the
LOCK position.
(3) Turn the ignition switch to the ON position.
(4) Within 20 seconds, aim a transmitter at the re-
ceiver dome and press the LOCK button for at least
5 seconds. Once the receiver accepts the program-
ming code, the driver's door will unlock.
(5) Once the first transmitter has been pro-
grammed, additional transmitters (up to 4) may be
programmed into the receiver. Within 20 seconds of
the previous transmitter programming, move the me-
chanical door lock lever to the LOCK position. Aimanother transmitter at the receiver dome and press
the LOCK button for at least 5 seconds. The door
lock will cycle again.
(6) To lock the programmed codes into the re-
ceiver, the ignition switch must be turned OFF and
back ON within 20 seconds after programming the
last transmitter's code. At that time, all previous
codes are erased from the module.
DIAGNOSING POWER DOOR LOCKS
NO DOOR LOCKS OPERATE, USING
TRANSMITTER
(1) Measure resistance at keyless entry module
terminal 10. Meter should read zero ohms. If not, re-
pair open to ground.
(2) Measure voltage at keyless entry module termi-
nal 1. Meter should read battery voltage.Battery
voltage must be at least 9 volts for this system to
operate.If not, repair open to #9 fuse.
(3) Jumper test leads keyless entry module termi-
nal 1 to terminal 3. Doors should lock. If OK, replace
module. If not, repair open from terminal 3 to lock
relay terminal 1.
(4) Jumper test leads keyless entry module termi-
nal 1 to terminal 4. Door should unlock. If OK, re-
place module. If not, repair open from terminal 4 to
unlock relay terminal 1.
TRANSMITTER SERVICE
If the receiver malfunctions, only the receiver will
have to be replaced. The new receiver will have to be
reprogrammed. If a transmitter is lost, replace the
transmitter and reprogram the receiver.
Batteries may not be supplied with some re-
placement transmitters. Be sure to check a re-
placement transmitter before attempting to
activate the system.
TRANSMITTER BATTERY REPLACEMENT
(1) Separate transmitter at middle seam (Fig. 2).
Fig. 2 Separate Transmitter Halves
Fig. 1 Keyless Entry Transmitter
JPOWER DOOR LOCKS 8P - 9