1995 JEEP YJ lights

MAINTENANCE SCHEDULES
INTRODUCTION
There are two maintenance schedules that show
proper service intervals for Jeep Cherokee and Jeep
Wrangler vehicles. Use the schedule that best de-
scribes the conditions the vehicle is operated under.
When mileage and time is listed, follow the interval
that occurs first.
ScheduleÐAlists all the scheduled maintenance
to be performed under normal operating conditions.
ScheduleÐBis a schedule for vehicles that are
usually operated under one or more of the following
conditions.
²Frequent short trip driving less than 5 miles (8
km).
²Frequent driving in dusty conditions.
²Trailer towing or heavy load hauling.
²Frequent long periods of engine idling.
²Sustained high speed operation.
²Desert operation.
²Frequent starting and stopping.
²Cold climate operation.
²Off road driving.
²Commercial service.
²Snow plow operation.
²More than half of vehicle operation occurs in
heavy city traffic during hot weather (above 90É F).
AT EACH STOP FOR GASOLINE
²Check engine oil level and add as required.
²Check windshield washer solvent and add as re-
quired.
ONCE A MONTH
²Check tire pressure and look for unusual tire wear
or damage.
²Check fluid levels of coolant reservoir, brake mas-
ter cylinder, power steering and transmission. Add
fluid as required.
²Check all lights and other electrical items for cor-
rect operation.
²Inspect battery and clean and tighten terminals as
required.
²Check rubber seals on each side of the radiator for
proper fit.
AT EACH OIL CHANGE
²Inspect exhaust system.
²Inspect brake hoses.
²Rotate the tires at each oil change interval shown
on ScheduleÐA: (7,500 Miles) or every other interval
shown on ScheduleÐB: (6,000 Miles).
²Check engine coolant level, hoses, and clamps.
²Lubricate 4x4 steering linkage.
²Lubricate propeller shaft universal joints and slip
spline, if equipped.After completion of off-road (4WD) operation, the
underside of the vehicle should be thoroughly in-
spected. Examine threaded fasteners for looseness.
HARSH SURFACE ENVIRONMENTS
After vehicle operation in a harsh surface environ-
ment, the following components should be inspected
and cleaned as soon as possible:
²Brake drums.
²Brake linings.
²Front wheel bearings (2WD vehicles only).
²Axle coupling joints.
This will prevent wear and/or unpredictable brake
action.
EMISSION CONTROL SYSTEM MAINTENANCE
The schedule emission maintenance listed inbold
typeon the following schedules, must be done at the
mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
SCHEDULEÐA
7,500 MILES (12 000 KM) OR AT 6 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage (4x4).
15,000 MILES (24 000 KM) OR AT 12 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage.
22,500 MILES (36 000 KM) OR AT 18 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage (4x4).
²Inspect brake linings.
30,000 MILES (48 000 KM) OR AT 24 MONTHS
²Replace air cleaner element.
²Replace spark plugs.
²Adjust belt tension on non-automatic tensioning
drive belts.
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage.
²Drain and refill automatic transmission.
²Drain and refill transfer case.
0 - 4 LUBRICATION AND MAINTENANCEJ

BRAKES
CONTENTS
page page
ABS BRAKE DIAGNOSIS................... 3
ABS OPERATION AND SERVICE............ 33
BRAKE FLUIDÐBRAKE BLEEDINGÐ
BRAKELINES AND HOSES............... 10
DISC BRAKES.......................... 45
DRUM BRAKES......................... 55
GENERAL INFORMATION.................. 1MASTER CYLINDERÐCOMBINATION VALVE . . 15
PARKING BRAKES....................... 60
POWER BRAKE BOOSTERÐBRAKE PEDALÐ
BRAKELIGHT SWITCH.................. 22
SERVICE BRAKE DIAGNOSIS............... 4
SPECIFICATIONS........................ 70
GENERAL INFORMATION
INDEX
page page
Antilock Brakes (ABS)....................... 1
Brake Components......................... 1
Brake Fluid/Lubricants/Cleaning Solvents......... 2
Brake Safety Precautions.................... 2Brake Warning Lights....................... 1
Brakelining Material........................ 1
Jeep Body Code Letters..................... 2
BRAKE COMPONENTS
Power assist front disc and rear drum brakes are
standard on Cherokee/Wrangler models. Disc brake
components consist of single piston calipers and ven-
tilated rotors. Rear drum brakes are dual shoe units
with cast brake drums.
The parking brake mechanism is lever and cable
operated. The cables are attached to levers on the
rear drum brake secondary shoes. The parking
brakes are operated by a foot pedal on YJ models and
a hand lever on XJ models.
A 205 mm dual diaphragm vacuum power brake
booster is used for all applications. Two master cylin-
ders are used; 4-cylinder YJ models have a one-piece
master cylinder. All other models have a two-piece
master cylinder with plastic reservoir.
All models are equipped with a combination valve.
The valve contains a pressure differential valve and
switch and a fixed rate rear proportioning valve.
BRAKELINING MATERIAL
Factory brakelining on all models consists of an or-
ganic base material combined with metallic particles.
The lining does not contain asbestos.
BRAKE WARNING LIGHTS
Cherokee/Wrangler models are equipped with one
or two brake warning lights. A red warning light is
standard on all models. An amber light is added on
models with ABS brakes. Both lights are located in
the instrument panel.
The red light is in circuit with the pressure differ-
ential switch (in the combination valve), and with the
parking brake switch. The light alerts the driver
when the parking brakes are applied, or when a
pressure differential exists between the front and
rear hydraulic systems. The light also illuminates for
a few seconds at start up as part of a bulb check.
The ABS warning light is amber in color and is lo-
cated in the same side of the instrument cluster as
the red warning light. The amber light only illumi-
nates when an ABS circuit fault occurs.
ANTILOCK BRAKES (ABS)
An antilock brake system (ABS) is available on
Cherokee/Wrangler models as an option. The system
is an electronically operated, all-wheel brake control
system. The ABS system is designed to prevent
wheel lockup during periods of high wheel slip brak-
ing. Refer to the antilock brake section for operation
and service information.
JBRAKES 5 - 1

BRAKELIGHT SWITCH REMOVAL
The brakelight switch is mounted in the pedal sup-
port bracket and is operated by the pedal. The switch
is secured in the bracket with a retainer (Fig. 30).
(1) Remove steering column cover and lower trim
panel for switch access, if necessary.
(2) Disconnect switch wire harness.
(3) Thread switch out of retainer, or rock switch
up/down and pull it rearward out of retainer.
(4) Inspect switch retainer, if equipped. Replace re-
tainer if worn, distorted, loose, or damaged.
BRAKELIGHT SWITCH INSTALLATION
(1) Insert replacement switch in retainer. Thread
switch into place or rock it up/down until switch
plunger touches brake pedal. Insert switch in bracket
and thread clip onto plunger to secure switch.
(2) Connect switch wires.
(3) Check switch operation. Adjust switch position
if necessary. Refer to procedures in this section.
(4) Install trim panels (if removed).
BRAKELIGHT SWITCH ADJUSTMENT
A plunger-type brakelight switch is used on XJ and
YJ models (Fig. 30). The switch plunger is actuated
directly by the brake pedal.
The switch internal contacts are open when the
brake pedal is in the released position. Brake appli-
cation moves the pedal away from the switch allow-
ing the plunger to extend. As the plunger extends,
the switch internal contacts close completing the cir-
cuit to the brakelights.
The switch is retained in the bracket by a clip. The
clip has tangs that seat in the threads of the switch
plunger barrel.
SWITCH ADJUSTMENT PROCEDURE
(1) Check switch adjustment. Move the brake
pedal forward by hand and note operation of the
switch plunger. Plunger should extend when pedalfree play is taken up and brake application begins. A
clearance of approximately 3 mm (1/8 in.) should ex-
ist between plunger and pedal at this point.
(a) If switch-to-pedal clearance is OK and brake-
lights operate correctly, adjustment is not required.
(b) If switch plunger does not extend and clear-
ance between pedal and plunger is insufficient, ad-
just switch position as described in step (2).
(2) Grasp brake pedal and pull it rearward as far
as possible. Switch plunger barrel will ``ratchet'' rear-
ward in retaining clip to correct position.
(3) Verify brakelight switch operation and proper
clearance between switch plunger and brake pedal.
CAUTION: Be very sure the brake pedal returns to a
fully released position after adjustment. The switch
can interfere with full pedal return if too far forward.
The result will be brake drag caused by partial
brake application.
Fig. 30 Brakelight Switch Mounting And Location
(XJ/YJ)
5 - 32 POWER BRAKE BOOSTERÐBRAKE PEDALÐBRAKELIGHT SWITCHJ

TACHOMETER
The tachometer gives an indication of engine speed
in Revolutions-Per-Minute (RPM). With the engine
running, the tachometer receives an engine speed
pulse signal from the Powertrain Control Module
(PCM). An electronic integrated circuit contained
within the tachometer reads and analyzes the pulse
signal. It then adjusts the ground path resistance of
one electromagnet in the gauge to control needle
movement. Frequency values for the pulse signal are
shown in a chart in Specifications.
TRIP ODOMETER
The trip odometer is driven by the same electronic
integrated circuit as the speedometer/odometer. How-
ever, by depressing the trip odometer reset knob on
the face of the speedometer, the trip odometer can be
reset to zero. The trip odometer is serviced only as a
part of the speedometer/odometer gauge assembly.
VOLTMETER
The voltmeter is connected in parallel with the bat-
tery. With the ignition switch ON, the voltmeter in-
dicates battery or generator output voltage,
whichever is greater.
INDICATOR LAMPS
Indicator lamps are located in two areas within the
cluster. Each of these areas is served by a separate
printed circuit and cluster connector. Those lamps in
the gauge area of the cluster share the gauge area
printed circuit and cluster connector A. Those lamps
in the tell-tale area of the cluster use the tell-tale
printed circuit and cluster (tell-tale) connector B.
Up to ten indicator lamps can be found in the tell-
tale area of the cluster. These lamps are arranged in
five stacked rows with two lamps in each row, located
to the driver's side of the main cluster.
ANTI-LOCK BRAKE SYSTEM LAMP
The Anti-Lock Brake System (ABS) lamp is
switched to ground by the ABS module. The module
lights the lamp when the ignition switch is turned to
the START position as a bulb test. The lamp will
stay on for 3 to 5 seconds after vehicle start-up to in-
dicate a system self-test is in process. If the lamp re-
mains on after start-up, or comes on and stays on
while driving, it may indicate that the ABS module
has detected a system malfunction or that the system
has become inoperative. Refer to Group 5 - Brakes
for more information.
BRAKE WARNING LAMP
The brake warning lamp warns the driver that the
parking brake is applied or that the pressures in the
two halves of the split brake hydraulic system are
unequal. With the ignition switch turned ON, batteryvoltage is supplied to one side of the indicator bulb. A
ground path for the bulb is provided by 3 switches.
The bulb will light when:
²the brake warning switch is closed (indicating un-
equal brake system hydraulic pressures possibly due
to brake fluid leakage)
²the ignition switch is in the START position (bulb
test)
²the parking brake switch is closed (parking brake
is applied).
Refer to Group 5 - Brakes for more information.
COOLANT TEMPERATURE WARNING LAMP
The coolant temperature warning lamp lights
whenever engine coolant temperature is too high.
Battery voltage is supplied to one side of the indica-
tor bulb when the ignition switch is turned ON. The
normally open coolant temperature switch is con-
nected to the other side of the bulb. When coolant
temperature is too high, the switch closes. This pro-
vides a ground path for the indicator bulb, which
causes it to light. The lamp is also grounded and
should light with the ignition switch in the START
position as a bulb test.
FOUR-WHEEL DRIVE INDICATOR LAMPS
PART TIME
On vehicles with Command-Trac 4WD, the Part
Time lamp lights when the transfer case is engaged
in the 4H or 4L position. On vehicles with Selec-Trac
4WD, the Part Time lamp lights when the transfer
case is engaged in the4X4PARTTIME or 4 LO po-
sition. Voltage is supplied to one side of the indicator
bulb. A switch in the transfer case is connected to the
other side of the indicator bulb. When the switch is
closed, a path to ground is provided and the indicator
bulb lights.
FULL TIME
The Full Time lamp is only operational on vehicles
equipped with Selec-Trac 4WD. The Full Time lamp
lights when the transfer case is engaged in the4X4
Full Time position. Voltage is supplied to one side of
the indicator bulb. A switch in the transfer case is
connected to the other side of the indicator bulb.
When the switch is closed, a path to ground is pro-
vided and the indicator bulb lights.
GENERATOR WARNING LAMP
The generator warning lamp lights with the igni-
tion switch turned to ON, but should go out when-
ever the engine is running. If the lamp comes on and
stays on while the engine is running, it indicates
that a charging system malfunction exists. One side
of the bulb is connected to ignition-switched battery
feed. The other side of the bulb is switched to ground
by the Powertrain Control Module (PCM).
JINSTRUMENT PANEL AND GAUGESÐXJ 8E - 3

HEADLAMP HIGH BEAM INDICATOR LAMP
The high beam indicator lamp is controlled by the
headlamp dimmer (multi-function) switch. One side
of the indicator bulb is grounded at all times. The
other side of the bulb receives battery feed through
the contacts of the dimmer switch when the multi-
function switch stalk is actuated to turn the head-
lamp high beams on. Refer to Group 8L - Lamps for
more information.
LOW FUEL WARNING LAMP
A Light-Emitting Diode (LED) on the face of the
fuel gauge will light when the fuel level falls below
approximately 4 gallons. A low fuel warning module
attached to the rear of the fuel gauge controls when
the LED will light. When the module senses 66.5
ohms or more resistance from the fuel level sending
unit for 10 continuous seconds, the LED will light.
When the module senses 63.5 ohms or less resistance
from the fuel level sending unit for 20 continuous
seconds, the LED is turned off.
LOW OIL PRESSURE WARNING LAMP
The low oil pressure warning lamp lights with the
ignition switch in the ON position and the engine not
running. The lamp should be off when the engine is
running. Battery voltage is supplied to one side of
the indicator bulb when the ignition switch is turned
ON. The warning lamp side of the combination oil
pressure sending unit is connected to the other side
of the bulb. When normal engine oil pressure is ap-
plied to the sending unit, resistance on the warning
lamp side is high and the lamp goes off. When engine
oil pressure is too low, resistance on the warning
lamp side of the sending unit is low, which causes
the bulb to light.
LOW WASHER FLUID WARNING LAMP
The low washer fluid warning lamp indicates when
the fluid level in the washer reservoir is too low. The
washer fluid level sensor uses a float in the reservoir
to monitor fluid level. The action of the float opens or
closes the switch within the sensor that provides ig-
nition-switched battery voltage to the lamp bulb. Re-
fer to Group 8K - Wiper and Washer Systems for
more information.
MALFUNCTION INDICATOR LAMP
The CHECK ENGINE or Malfunction Indicator
Lamp (MIL) lights each time the ignition switch is
turned ON, and stays on for 3 seconds as a bulb test.
If the Powertrain Control Module (PCM) receives an
incorrect signal or no signal from certain fuel oremission system related circuits or components, the
lamp is turned on. This will indicate that the PCM
has recorded a Diagnostic Trouble Code (DTC) in
electronic memory for a circuit or component mal-
function. Refer to Group 14 - Fuel System for more
information.
SEAT BELT REMINDER LAMP
The seat belt reminder lamp lights for 4 to 8 sec-
onds after the ignition switch is turned to the ON po-
sition. A timer in the chime/buzzer module controls
ignition-switched battery feed to the lamp. Refer to
Group 8U - Chime/Buzzer Warning Systems for more
information.
TURN SIGNAL INDICATOR LAMPS
The left and right turn signal indicator lamps are
controlled by the turn signal and hazard warning
(multi-function) switches. One side of the bulb for
each lamp is grounded at all times. The other side of
the bulb receives battery feed through the contacts of
the multi-function switch when the turn signal lever
(multi-function switch stalk) or hazard warning but-
ton are actuated. Refer to Group 8J - Turn Signal
and Hazard Warning Systems for more information.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. Ground feed for
the lamp is switched by the Powertrain Control Mod-
ule (PCM). The lamp lights to indicate when the
driver should shift to the next highest gear for best
fuel economy. The PCM will turn the lamp off after 3
to 5 seconds if the upshift is not performed. The lamp
will remain off until the vehicle stops accelerating
and is brought back to the range of lamp operation,
or until the transmission is shifted into another gear.
The indicator lamp is normally on when the igni-
tion switch is turned ON and is turned off when the
engine is started. The lamp will be turned on during
vehicle operation according to engine speed and load.
CLUSTER ILLUMINATION LAMPS
All cluster illumination lamps receive battery feed
from the instrument lamps fuse in the fuseblock
module through the panel dimmer rheostat of the
headlamp switch. When the park or headlamps are
on, the cluster illumination lamps light. Illumination
brightness can be adjusted by rotating the headlamp
switch knob (clockwise to dim, counterclockwise to
brighten).
8E - 4 INSTRUMENT PANEL AND GAUGESÐXJJ

The gauge needle moves as the movable permanent
magnet aligns itself to the changing magnetic fields
created around it by the electromagnets.
COOLANT TEMPERATURE GAUGE
The coolant temperature gauge gives an indication
of engine coolant temperature. The coolant tempera-
ture sending unit is a thermistor that changes elec-
trical resistance with changes in engine coolant
temperature. High sending unit resistance causes
low coolant temperature readings. Low resistance
causes high coolant temperature readings. Sending
unit resistance values are shown in a chart in Spec-
ifications.
FUEL GAUGE
The fuel gauge gives an indication of the level of
fuel in the fuel tank. The fuel gauge sending unit has
a float attached to a swing-arm in the fuel tank. The
float moves up or down within the fuel tank as fuel
level changes. As the float moves, an electrical con-
tact on the swing-arm wipes across a resistor coil,
which changes sending unit resistance. High sending
unit resistance causes high fuel level readings. Low
resistance causes low fuel level readings. Sending
unit resistance values are shown in a chart in Spec-
ifications.
OIL PRESSURE GAUGE
The oil pressure gauge gives an indication of en-
gine oil pressure. The combination oil pressure send-
ing unit contains a flexible diaphragm. The
diaphragm moves in response to changes in engine
oil pressure. As the diaphragm moves, sending unit
resistance increases or decreases. High resistance on
the gauge side of the sending unit causes high oil
pressure readings. Low resistance causes low oil
pressure readings. Sending unit resistance values are
shown in a chart in Specifications.
SPEEDOMETER/ODOMETER
The speedometer/odometer give an indication of ve-
hicle speed and travel distance. The speedometer re-
ceives a vehicle speed pulse signal from the Vehicle
Speed Sensor (VSS). An electronic integrated circuit
contained within the speedometer reads and analyzes
the pulse signal. It then adjusts the ground path re-
sistance of one electromagnet in the gauge to control
needle movement. It also sends signals to an electric
stepper motor to control movement of the odometer
number rolls. Frequency values for the pulse signal
are shown in a chart in Specifications.
The VSS is mounted to an adapter near the trans-
fer case output shaft. The sensor is driven through
the adapter by a speedometer pinion gear. The
adapter and pinion vary with transmission, axle ratio
and tire size. Refer to Group 21 - Transmission and
Transfer Case for more information.
TACHOMETER
The tachometer gives an indication of engine speed
in Revolutions-Per-Minute (RPM). With the engine
running, the tachometer receives an engine speed
pulse signal from the Powertrain Control Module
(PCM). An electronic integrated circuit contained
within the tachometer reads and analyzes the pulse
signal. It then adjusts the ground path resistance of
one electromagnet in the gauge to control needle
movement. Frequency values for the pulse signal are
shown in a chart in Specifications.
TRIP ODOMETER
The trip odometer is driven by the same electronic
integrated circuit as the speedometer/odometer. How-
ever, by depressing the trip odometer reset knob on
the face of the speedometer, the trip odometer can be
reset to zero. The trip odometer is serviced only as a
part of the speedometer/odometer gauge assembly.
VOLTMETER
The voltmeter is connected in parallel with the bat-
tery. With the ignition switch ON, the voltmeter in-
dicates battery or generator output voltage,
whichever is greater.
INDICATOR LAMPS
All indicator lamps, except the four-wheel drive in-
dicator, are located in the main cluster tell-tale area
above the steering column opening. Each of the
lamps is served by the main cluster printed circuit
and cluster connector. The four-wheel drive indicator
lamp is located in the gauge package cluster and is
served by the gauge package printed circuit and clus-
ter connector.
Up to eleven indicator lamps can be found in the
tell-tale area of the main cluster. These lamps are ar-
ranged in two rows, with six lamps in the upper row
and five lamps in the lower row.
ANTI-LOCK BRAKE SYSTEM LAMP
The Anti-Lock Brake System (ABS) lamp is
switched to ground by the ABS module. The module
lights the lamp when the ignition switch is turned to
the START position as a bulb test. The lamp will
stay on for 3 to 5 seconds after vehicle start-up to in-
dicate a system self-test is in process. If the lamp re-
mains on after start-up, or comes on and stays on
while driving, it may indicate that the ABS module
has detected a system malfunction or that the system
has become inoperative. Refer to Group 5 - Brakes
for more information.
BRAKE WARNING LAMP
The brake warning lamp warns the driver that the
parking brake is applied or that the pressures in the
two halves of the split brake hydraulic system are
unequal. With the ignition switch turned ON, battery
JINSTRUMENT PANEL AND GAUGESÐYJ 8E - 25

voltage is supplied to one side of the indicator bulb. A
ground path for the bulb is provided by 3 switches.
The bulb will light when:
²the brake warning switch is closed (indicating un-
equal brake system hydraulic pressures possibly due
to brake fluid leakage)
²the ignition switch is in the START position (bulb
test)
²the parking brake switch is closed (parking brake
is applied).
Refer to Group 5 - Brakes for more information.
FOUR-WHEEL DRIVE INDICATOR LAMP
This lamp lights when the transfer case is engaged
in the 4H or 4L position. Voltage is supplied to one
side of the indicator bulb. A switch on the front axle
disconnect housing is connected to the other side of
the indicator bulb. When the switch is closed, a path
to ground is provided and the indicator bulb lights.
HEADLAMP HIGH BEAM INDICATOR LAMP
The high beam indicator lamp is controlled by the
headlamp dimmer switch. One side of the indicator
bulb is grounded at all times. The other side of the
bulb receives battery feed through the contacts of the
dimmer switch when the turn signal switch lever is
actuated to turn the headlamp high beams on. Refer
to Group 8L - Lamps for more information.
MALFUNCTION INDICATOR LAMP
The CHECK ENGINE or Malfunction Indicator
Lamp (MIL) lights each time the ignition switch is
turned ON, and stays on for 3 seconds as a bulb test.
If the Powertrain Control Module (PCM) receives an
incorrect signal or no signal from certain fuel or
emission system related circuits or components, the
lamp is turned on. This will indicate that the PCM
has recorded a Diagnostic Trouble Code (DTC) in
electronic memory for a circuit or component mal-
function. Refer to Group 14 - Fuel System for more
information.
SEAT BELT REMINDER LAMP
The seat belt reminder lamp lights for 4 to 8 sec-
onds after the ignition switch is turned to the ON po-sition. A timer in the chime/buzzer module controls
ignition-switched battery feed to the lamp. Refer to
Group 8U - Chime/Buzzer Warning Systems for more
information.
TURN SIGNAL INDICATOR LAMPS
The left and right turn signal indicator lamps are
controlled by the turn signal and hazard warning
switches. One side of the bulb for each lamp is
grounded at all times. The other side of the bulb re-
ceives battery feed through the contacts of the turn
signal switch, when the turn signal lever or hazard
warning button are actuated. Refer to Group 8J -
Turn Signal and Hazard Warning Systems for more
information.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. Ground feed for
the lamp is switched by the Powertrain Control Mod-
ule (PCM). The lamp lights to indicate when the
driver should shift to the next highest gear for best
fuel economy. The PCM will turn the lamp off after 3
to 5 seconds if the upshift is not performed. The lamp
will remain off until the vehicle stops accelerating
and is brought back to the range of lamp operation,
or until the transmission is shifted into another gear.
The indicator lamp is normally on when the igni-
tion switch is turned ON and is turned off when the
engine is started. The lamp will be turned on during
vehicle operation according to engine speed and load.
CLUSTER ILLUMINATION LAMPS
All cluster illumination lamps receive battery feed
from the instrument lamps fuse in the fuseblock
module through the panel dimmer switch. When the
park or headlamps are on, the cluster illumination
lamps light. Illumination brightness can be adjusted
by rotating the panel dimmer thumb-wheel, which is
next to the headlamp switch.
8E - 26 INSTRUMENT PANEL AND GAUGESÐYJJ

TURN SIGNAL AND HAZARD WARNING SYSTEMS
CONTENTS
page page
DIAGNOSIS............................. 3
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 5
GENERAL INFORMATION
Following are general descriptions of the major
components in the XJ (Cherokee)/YJ (Wrangler)
model turn signal and hazard warning systems. Refer
to Group 8W - Wiring Diagrams for complete circuit
descriptions and diagrams.
TURN SIGNAL SYSTEM
With the ignition switch in the ON or ACCESSORY
position and the turn signal switch lever (YJ) or
multi-function switch control lever (XJ) moved up
(right turn) or down (left turn), the turn signal sys-
tem is activated.
When the turn signal system is activated, the se-
lected (right or left) turn signal indicator lamp, front
park/turn signal lamp and rear tail/stop/turn signal
lamp bulb filaments will flash. With the headlamp
switch in the OFF position, the turn and front side
marker lamps flash in unison. With the headlamp
switch in the ON position, the turn and front side
marker lamps flash alternately.
HAZARD WARNING SYSTEM
The hazard warning is activated by a switch button
located below the ignition lock cylinder (YJ) or on the
top of the steering column (XJ) between the steering
wheel and the instrument panel. The hazard warning
flasher (YJ) or combination flasher (XJ) receives bat-
tery feed at all times, and the system is functional
regardless of ignition switch position. The hazard
warning switch button is identified with a double
triangle. On YJ models, push the switch button in to
activate the hazard warning system and pull the
button out to turn system off. On XJ models, push in
on the switch button to latch the switch and activate
the hazard warning system, and push in on the
switch button again to unlatch the switch and turn
the system off.
When the hazard warning system is activated, all
(right and left) turn signal indicator, front park/turn
signal lamp and rear tail/stop/turn signal lamp bulb
filaments will flash.
TURN SIGNAL FLASHER (YJ ONLY)
The turn signal flasher is located in the fuseblock
module. It contains one fixed contact point and one
contact point attached to a flexible bimetal arm. The
contact points are normally closed. When a turn sig-
nal is activated, current flows through the flasher. As
current flows through the bimetal arm it heats and
flexes to pull the contact points open, stopping cur-
rent flow. As the bimetal arm cools it straightens,
until the contact points close and the cycle repeats.
The standard flasher is designed to handle the cur-
rent flow requirements of the factory installed light-
ing. If supplemental lighting is added to the turn
signal circuits such as when towing a trailer with
lights, the current flow through the flasher increases.
This causes the flash rate to increase. It is recom-
mended that the standard flasher be replaced with a
heavy-duty (hazard warning) flasher when supple-
mental lighting is added.
However, when a turn signal bulb fails with a stan-
dard flasher, the remaining bulbs in that circuit will
light, but not flash. This will give the driver an indi-
cation to check the turn signal bulbs. Because a
heavy-duty flasher has different internal circuitry, a
failed bulb will not prevent the remaining bulbs in
the circuit from flashing. Therefore, it is recom-
mended that an occasional visual inspection of exte-
rior turn signal lamp operation be performed when a
heavy-duty flasher is installed.
HAZARD WARNING FLASHER (YJ ONLY)
The hazard warning flasher is located in the fuse-
block module. The hazard warning flasher contains
two normally open contact points mounted to two
flexible arms. A bimetal strip is attached between the
two arms. When the hazard warning is activated,
current flows through the flasher. As the current
flows through the bimetal strip it heats and pulls the
flexible arms together until the contact points close,
JTURN SIGNAL AND HAZARD WARNING SYSTEMS 8J - 1