1995 JEEP YJ coolant level

WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove the radiator pressure cap from
the filler neck and check the coolant level. Push
down on the cap to disengage it from the stop tabs.
Wipe the inner part of the filler neck and examine
the lower inside sealing seat for nicks, cracks, paint,
dirt and solder residue. Inspect the reserve/overflow
tank tube for internal obstructions. Insert a wire
through the tube to be sure it is not obstructed.
Inspect the cams on the outside part of the filler
neck. If the cams are bent, seating of pressure cap
valve and tester seal will be affected. Replace cap if
cams are bent.
Attach pressure tester 7700 (or an equivalent) to
the radiator filler neck (Fig. 21).Operate the tester pump to apply 124 kPa (18 psi)
pressure to the system. If the hoses enlarge exces-
sively or bulge while testing, replace as necessary.
Observe the gauge pointer and determine the condi-
tion of the cooling system according to the following
criteria:
²Holds Steady: If the pointer remains steady for
two minutes, there are no serious coolant leaks in
the system. However, there could be an internal leak
that does not appear with normal system test pres-
sure. Inspect for interior leakage or do the Internal
Leakage Test. Do this if it is certain that coolant is
being lost and no leaks can be detected.
²Drops Slowly: Shows a small leak or seepage is oc-
curring. Examine all connections for seepage or slight
leakage with a flashlight. Inspect the radiator, hoses,
gasket edges and heater. Seal any small leak holes
with a Sealer Lubricant or equivalent. Repair leak
holes and reinspect the system with pressure ap-
plied.
²Drops Quickly: Shows that a serious leakage is oc-
curring. Examine the system for serious external
leakage. If no leaks are visible, inspect for internal
leakage. Large radiator leak holes should be repaired
by a reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove the engine oil pan drain plug and drain a
small amount of engine oil. Coolant, being heavier
than engine oil, will drain first. Another way of test-
ing is to operate the engine and check for water glob-
ules on the engine oil dipstick. Also inspect the
automatic transmission oil dipstick for water glob-
ules. Inspect the automatic transmission fluid cooler
for leakage. Operate the engine without the pressure
cap on the radiator until thermostat opens.
Attach a pressure tester to the filler neck. If pres-
sure builds up quickly, a leak exists as a result of a
faulty cylinder head gasket or crack in the engine.
Repair as necessary.
WARNING: DO NOT ALLOW PRESSURE TO EX-
CEED 124 KPA (18 PSI). TURN THE ENGINE OFF.
TO RELEASE THE PRESSURE, ROCK THE TESTER
FROM SIDE TO SIDE. WHEN REMOVING THE
TESTER, DO NOT TURN THE TESTER MORE THAN
1/2 TURN IF THE SYSTEM IS UNDER PRESSURE.
If there is no immediate pressure increase, pump
the pressure tester until the indicated pressure is
within the system range. Vibration of the gauge
pointer indicates compression or combustion leakage
into the cooling system.
WARNING: DO NOT DISCONNECT THE SPARK
PLUG WIRES WHILE THE ENGINE IS OPERATING.
Fig. 20 Leak Detection Using Black LightÐTypical
Fig. 21 Pressurizing SystemÐTypical
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 23

CAUTION: Do not operate the engine with a spark
plug shorted for more than a minute. The catalytic
converter may be damaged.
Isolate the compression leak by shorting each
spark plug to the cylinder block. The gauge pointer
should stop or decrease vibration when spark plug
for leaking cylinder is shorted. This happens because
of the absence of combustion pressure.
COMBUSTION LEAKAGE TEST (WITHOUT
PRESSURE TESTER)
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
Drain sufficient coolant to allow for thermostat re-
moval. Refer to Thermostat Replacement. Disconnect
the water pump drive belt.
Disconnect the upper radiator hose from the ther-
mostat housing. Remove the housing and thermostat.
Install the thermostat housing.
Add coolant to the radiator to bring the level to
within 6.3 mm (1/4 in) of the top of the thermostat
housing.
CAUTION: Avoid overheating. Do not operate the
engine for an excessive period of time. Open the
draincock immediately after the test to eliminate
boil over of coolant.
Start the engine and accelerate rapidly three times
(to approximately 3000 rpm) while observing the
coolant. If internal engine combustion gases are leak-
ing into the cooling system, bubbles will appear in
the coolant. If bubbles do not appear, there is no in-
ternal combustion gas leakage.
COOLANT RESERVE/OVERFLOW SYSTEM
The system works along with the radiator pressure
cap. This is done by using thermal expansion and
contraction of the coolant to keep the coolant free of
trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/adjust-
ing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover mi-
nor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-ant will then be drawn from the coolant tank and re-
turned to a proper level in the radiator.
The coolant reserve/overflow system consists of a
radiator mounted pressurized cap, a plastic reserve/
overflow tank (Figs. 22, 23 or 24), a tube (hose) con-
necting the radiator and tank, and an overflow tube
on the side of the tank.
Fig. 22 Reserve/Overflow TankÐYJ Models
Fig. 23 Reserve/Overflow TankÐXJ ModelsÐExcept
Right Hand Drive
7 - 24 COOLING SYSTEM SERVICE PROCEDURESJ

WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 27). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 28). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.XJ MODELS WITH 2.5L 4-CYLINDER ENGINE
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Observe the previousWARNINGS.Remove ra-
diator cap.
(3) Position drain pan under draincock. Open radi-
ator draincock. Drain radiator.
(4) Remove radiator upper and lower hose clamps
(Figs. 27 and 28). Remove hoses.
(5) Remove E-clip from alignment dowel at radia-
tor lower mounting bracket (Fig. 29).
(6) Disconnect coolant reserve/overflow tank hose
from radiator.
(7) Remove four radiator fan shroud mounting
bolts (Fig. 29). Push shroud back against front of en-
gine.
(8) If equipped, disconnect and plug automatic
transmission fluid cooler lines. Refer to Group 21,
Transmission for procedures.
(9) Remove two radiator top mounting bolts (Fig.
29).
(10) (a) If equipped with air conditioning, remove
the radiator grille mounting screws and remove grill.
Refer to Group 23, Body for procedures.
(b) If equipped, remove the air conditioning con-
denser-to-radiator mounting bolt. Use an open end
wrench to remove bottom bolts (Fig. 30).
(11) Lift radiator straight up and out of vehicle.
Take care not to damage radiator fins. When remov-
ing radiator, note position of the rubber seals located
on the top, bottom and sides of radiator (Fig. 29). To
prevent possible overheating, these seals must be in-
stalled to their original positions.
INSTALLATION
(1) Install radiator behind air conditioning con-
denser with bottom alignment dowel inserted into ra-
diator lower mounting bracket (Fig. 29).
(2) Install E-clip to radiator alignment dowel (Fig.
29).
(3) Tighten the four condenser-to-radiator mount-
ing bolts to 6.2 Nzm (55 in. lbs.) torque.
(4) If removed, install radiator grille.
(5) Tighten radiator top mounting bolts to 6 Nzm
(55 in. lbs.) torque.
(6) If equipped, connect automatic transmission
fluid cooler lines to radiator. Refer to Group 21,
Transmission for procedures.
(7) Install the radiator fan shroud.
(8) Connect the coolant reserve/overflow tank hose.
(9) Connect radiator hoses and install hose clamps.
(10) Connect negative battery cable.
(11) Close the draincock.
(12) Fill cooling system with correct coolant.
(13) Install radiator cap.
(14) Check and adjust automatic transmission
fluid level (if equipped).
Fig. 27 Hose Clamp ToolÐTypical
Fig. 28 Clamp Number/Letter Location
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 27

(13) Remove four radiator upper crossmember
bolts (Fig. 32) and remove upper crossmember.
(14) If equipped with air conditioning, separate ra-
diator from condenser by removing condenser-to-radi-
ator mounting brackets (Fig. 33).
(15) Lift radiator straight up and out of engine
compartment taking care not to damage fins.
INSTALLATION
The radiator is supplied with two alignment dowels
(Figs. 32 or 34). They are located on the bottom tank
and fit into rubber grommets in the radiator lower
crossmember.
(1) Lower radiator into engine compartment. Posi-
tion alignment dowels into rubber grommets in radi-
ator lower crossmember (Figs. 32 or 34).
(2) If equipped with air conditioning, attach con-
denser to radiator with mounting brackets (Fig. 33).
(3) Install radiator upper crossmember and four
mounting bolts.
(4) Install radiator upper crossmember-to-isolator
nuts. Tighten nuts to 10 Nzm (86 in. lbs.) torque. If
isolator-to-radiator nuts had been removed, tighten
them to 5 Nzm (47 in. lbs.) torque.
(5) Install hood latch striker. Note previously
marked position.
(6) Connect radiator upper and lower hoses.
(7) If equipped, connect automatic transmission
fluid cooler lines. Refer to Group 21, Transmissions
for procedures. If equipped with remote cooler, attach
cooler line to bracket at bottom of radiator.
(8) Install electric cooling fan (if equipped). Insert
alignment tabs at bottom of fan shroud into slots inbracket at bottom of radiator. Tighten mounting bolts
to3Nzm (31 in. lbs.) torque.
(9) Connect electric cooling fan electrical connector.
(10) Install mechanical cooling fan shroud. Insert
alignment tabs at bottom of shroud into slots in
bracket at bottom of radiator. Tighten mounting bolts
to3Nzm (31 in. lbs.) torque.
(11) Close radiator draincock.
(12) Install grille.
(13) Connect negative battery cable.
(14) Fill cooling system with correct coolant. Refer
to the Coolant section of this group.
(15) Install pressure cap.
(16) Check and adjust automatic transmission
fluid level (if equipped).
YJ MODELS
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 27). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
Fig. 33 Condenser-to-Radiator Mounting BracketsÐ
XJ with 4.0L 6- Cylinder Engine
Fig. 34 Radiator InstallationÐXJ Models with 4.0L
6-Cylinder Engine
7 - 30 COOLING SYSTEM SERVICE PROCEDURESJ

(10) Check and adjust automatic transmission
fluid level (if equipped).
COOLING SYSTEM HOSES
Rubber hoses route coolant to and from the radia-
tor, intake manifold and heater core. All XJ models
equipped with air conditioning have a coolant control
valve. This is located in-line with the heater core in-
let and outlet hoses. It controls coolant flow to the
heater core when the air conditioning system is in
operation.
Radiator lower hoses are spring-reinforced to pre-
vent collapse from water pump suction at moderate
and high engine speeds.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 36). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 37). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
Inspect the hoses at regular intervals. Replace
hoses that are cracked, feel brittle when squeezed, or
swell excessively when the system is pressurized.
For all vehicles: In areas where specific routing
clamps are not provided, be sure that hoses are posi-
tioned with sufficient clearance. Check clearance
from exhaust manifolds and pipe, fan blades, drive
belts and sway bars. Improperly positioned hoses can
be damaged, resulting in coolant loss and engine
overheating.Ordinary worm gear type hose clamps (when
equipped) can be removed with a straight screw-
driver or a hex socket.To prevent damage to
hoses or clamps, the hose clamps should be
tightened to 4 Nzm (34 in. lbs.) torque. Do not
over tighten hose clamps.
When performing a hose inspection, inspect the ra-
diator lower hose for proper position and condition of
the internal spring.
COOLING SYSTEM FANS
Also refer to either the Viscous Fan Drive and/or
the Auxiliary Electric Cooling FanÐXJ Models With
4.0L Engine sections for additional information.
All models are equipped with a mechanical temper-
ature controlled fan. This thermal viscous fan drive
(Fig. 38) is a torque-and-temperature-sensitive clutch
unit. It automatically increases or decreases fan
speed to provide proper engine cooling. XJ models
equipped with a 4.0L 6-cylinder engine may also
have an auxiliary electrical cooling fan. This is with
models that have air conditioning and/or heavy duty
cooling.
REMOVAL
Some engines have the mechanical fan/viscous fan
drive assembly mounted directly to the water pump
hub (Fig. 38). It may also be mounted to a hub/bear-
ing attached to an aluminum bracket on the right
front side of engine (Fig. 39).
(1) Loosen but do not remove at this time, the four
fan hub mounting nuts (Figs. 38 or 39).
Fig. 36 Hose Clamp ToolÐTypical
Fig. 37 Clamp Number/Letter Location
7 - 32 COOLING SYSTEM SERVICE PROCEDURESJ

VISCOUS FAN DRIVE
DESCRIPTION AND OPERATION
Also refer to the previous section on Cooling Sys-
tem Fans.
The thermal viscous fan drive (Fig. 38 or 39) is a
silicone-fluid-filled coupling used to connect the fan
blades to either the engine or the water pump shaft.
The coupling allows the fan to be driven in a normal
manner. This is done at low engine speeds while lim-
iting the top speed of the fan to a predetermined
maximum level at higher engine speeds.
A thermostatic bimetallic spring coil is located on
the front face of the viscous fan drive unit (a typical
viscous unit is shown in figure 40). This spring coil
reacts to the temperature of the radiator discharge
air. It engages the viscous fan drive for higher fan
speed if the air temperature from the radiator rises
above a certain point. Until additional engine cooling
is necessary, the fan will remain at a reduced rpm re-
gardless of engine speed.
Only when sufficient heat is present, will the vis-
cous fan drive engage. This is when the air flowing
through the radiator core causes a reaction to the bi-
metallic coil. It then increases fan speed to provide
the necessary additional engine cooling.
Once the engine has cooled, the radiator discharge
temperature will drop. The bimetallic coil again re-
acts and the fan speed is reduced to the previous dis-
engaged speed.
CAUTION: Engines equipped with serpentine drive
belts have reverse rotating fans and viscous fan
drives. They are marked with the word REVERSE to
designate their usage. Installation of the wrong fan
or viscous fan drive can result in engine overheat-
ing.CAUTION: If the viscous fan drive is replaced be-
cause of mechanical damage, the cooling fan
blades should also be inspected. Inspect for fatigue
cracks, loose blades, or loose rivets that could
have resulted from excessive vibration. Replace fan
blade assembly if any of these conditions are
found. Also inspect water pump bearing and shaft
assembly for any related damage due to a viscous
fan drive malfunction.
NOISE
It is normal for fan noise to be louder (roar-
ing) when:
²The underhood temperature is above the engage-
ment point for the viscous drive coupling. This may
occur when ambient (outside air temperature) is very
high.
²Engine loads and temperatures are high such as
when towing a trailer.
²Cool silicone fluid within the fan drive unit is be-
ing redistributed back to its normal disengaged
(warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold
engine.
LEAKS
Viscous fan drive operation is not affected by small
oil stains near the drive bearing. If leakage appears
excessive, replace the fan drive unit.
TESTING
If the fan assembly free-wheels without drag (the
fan blades will revolve more than five turns when
spun by hand), replace the fan drive. This spin test
must be performed when the engine is cool.
For the following test, the cooling system must be
in good condition. It also will ensure against exces-
sively high coolant temperature.
WARNING: BE SURE THAT THERE IS ADEQUATE
FAN BLADE CLEARANCE BEFORE DRILLING.
(1) Drill a 3.18-mm (1/8-in) diameter hole in the
top center of the fan shroud.
(2) Obtain a dial thermometer with an 8 inch stem
(or equivalent). It should have a range of -18É-to-
105ÉC (0É-to-220É F). Insert thermometer through the
hole in the shroud. Be sure that there is adequate
clearance from the fan blades.
(3) Connect a tachometer and an engine ignition
timing light (timing light is to be used as a strobe
light).
(4) Block the air flow through the radiator. Secure
a sheet of plastic in front of the radiator (or air con-
ditioner condenser). Use tape at the top to secure the
plastic and be sure that the air flow is blocked.
Fig. 40 Typical Viscous Fan Drive
7 - 34 COOLING SYSTEM SERVICE PROCEDURESJ

The high-line cluster includes the following gauges:
²coolant temperature gauge
²fuel gauge
²oil pressure gauge
²speedometer/odometer
²tachometer
²trip odometer
²voltmeter.
The high-line cluster includes provisions for the fol-
lowing indicator lamps:
²anti-lock brake system lamp
²brake warning lamp
²four-wheel drive indicator lamps
²headlamp high beam indicator lamp
²low fuel warning lamp
²low washer fluid warning lamp
²malfunction indicator (Check Engine) lamp
²seat belt reminder lamp
²turn signal indicator lamps
²upshift indicator lamp.
GAUGES
With the ignition switch in the ON or START posi-
tion, voltage is supplied to all gauges through the in-
strument cluster gauge area printed circuit. With the
ignition switch in the OFF position, voltage is not
supplied to the gauges. A gauge pointer may remain
within the gauge scale after the ignition switch is
OFF. However, the gauges do not accurately indicate
any vehicle condition unless the ignition switch is
ON.
All gauges except the odometer are air core mag-
netic units. Two fixed electromagnetic coils are lo-
cated within the gauge. These coils are wrapped at
right angles to each other around a movable perma-
nent magnet. The movable magnet is suspended
within the coils on one end of a shaft. The gauge nee-
dle is attached to the other end of the shaft.
One of the coils has a fixed current flowing through
it to maintain a constant magnetic field strength.
Current flow through the second coil changes, which
causes changes in its magnetic field strength. The
current flowing through the second coil can be
changed by:
²a variable resistor-type sending unit (fuel level,
coolant temperature, or oil pressure)
²changes in electrical system voltage (voltmeter)
²electronic control circuitry (speedometer/odometer,
tachometer).
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 coolanttemperature. High sending unit resistance causes
low coolant temperature readings. Low resistance
causes high coolant temperature readings.
The gauge will read at the high end of the scale
when the ignition switch is turned to the START po-
sition. This is caused by the bulb test circuit wiring
provision. The same wiring is used for the high-line
cluster with a coolant temperature gauge and the
low-line cluster with a coolant temperature warning
lamp. Sending unit resistance values are shown in a
chart in Specifications.
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 low fuel level readings. Low
resistance causes high 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 gives an indication of
vehicle speed and travel distance. The speedometer
receives 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-
mission (two-wheel drive) or transfer case (four-wheel
drive) output shaft. The sensor is driven through the
adapter by a speedometer pinion gear. The adapter
and pinion vary with transmission, transfer case,
axle ratio and tire size. Refer to Group 21 - Trans-
mission and Transfer Case for more information.
8E - 2 INSTRUMENT PANEL AND GAUGESÐXJJ

INSTRUMENT PANEL AND GAUGESÐYJ
CONTENTS
page page
INSTRUMENT PANEL AND GAUGESÐYJ..... 22
DIAGNOSIS............................ 23
GENERAL INFORMATION................. 20SERVICE PROCEDURES.................. 31
SPECIFICATIONS........................ 39
GENERAL INFORMATION
Following are general descriptions of major instru-
ment panel components. Refer to Group 8W - Wiring
Diagrams for complete circuit descriptions and dia-
grams.
INSTRUMENT PANEL
Modular instrument panel construction allows all
gauges and controls to be serviced from the front of
the panel. In addition, most instrument panel wiring
and heater components can be accessed without com-
plete instrument panel removal.
Removal of the left instrument cluster bezel allows
access to the main cluster assembly and most
switches. Removal of the center cluster bezel allows
access to the gauge package cluster assembly, the
heater controls, and the radio. Removal of the cluster
assemblies allows access to the individual gauges, il-
lumination and indicator lamp bulbs, printed cir-
cuits, and most wiring.
INSTRUMENT CLUSTERS
The instrument cluster used on YJ (Wrangler) mod-
els consists of two separate assemblies. The main
cluster assembly is located on the left side of the in-
strument panel, centered over the steering column
opening. The gauge package cluster assembly is lo-
cated near the center of the instrument panel. Each
cluster assembly is served by a separate printed cir-
cuit and wiring connector. Some variations of each
cluster exist due to optional equipment and regula-
tory requirements.
The main cluster assembly includes a speedometer/
odometer/trip odometer and a tachometer. It also in-
cludes provisions for the following indicator lamps:
²anti-lock brake system lamp
²brake warning lamp
²headlamp high beam indicator lamp
²malfunction indicator (Check Engine) lamp
²seat belt reminder lamp²turn signal indicator lamps
²upshift indicator lamp.
The gauge package cluster assembly includes a
four-wheel drive indicator lamp and the following
gauges:
²coolant temperature gauge
²fuel gauge
²oil pressure gauge
²voltmeter.
GAUGES
With the ignition switch in the ON or START posi-
tion, voltage is supplied to all gauges through the
two cluster printed circuits. With the ignition switch
in the OFF position, voltage is not supplied to the
gauges. A gauge pointer may remain within the
gauge scale after the ignition switch is OFF. How-
ever, the gauges do not accurately indicate any vehi-
cle condition unless the ignition switch is ON.
All gauges except the odometer are air core mag-
netic units. Two fixed electromagnetic coils are lo-
cated within the gauge. These coils are wrapped at
right angles to each other around a movable perma-
nent magnet. The movable magnet is suspended
within the coils on one end of a shaft. The gauge nee-
dle is attached to the other end of the shaft.
One of the coils has a fixed current flowing through
it to maintain a constant magnetic field strength.
Current flow through the second coil changes, which
causes changes in its magnetic field strength. The
current flowing through the second coil can be
changed by:
²a variable resistor-type sending unit (fuel level,
coolant temperature, or oil pressure)
²changes in electrical system voltage (voltmeter)
²electronic control circuitry (speedometer/odometer,
tachometer).
8E - 24 INSTRUMENT PANEL AND GAUGESÐYJJ