1995 JEEP YJ light

(2) Check the position of the slot on the oil pump
gear. On the 2.5L engine, it should be just slightly
before (counterclockwise of) the 10 o'clock position
(Fig. 10). On the 4.0L engine, it should be just
slightly before (counterclockwise of) the 11 o'clock po-
sition (Fig. 11). If not, place a flat blade screwdriver
into the oil pump gear and rotate it into the proper
position.
(3) Factory replacement distributors are equipped
with a plastic alignment pin already installed (Fig.
7). This pin is used to temporarily hold the rotor to
the cylinder number 1 firing position during distrib-
utor installation. If this pin is in place, proceed to
step number 8. If not, proceed to step number 4.
(4) If the original distributor is to be reinstalled,
such as during engine overhaul, the plastic pin will
not be available. A 3/16 inch drift pin punch tool may
be substituted for the plastic pin.
(5) Remove the camshaft position sensor from the
distributor housing. Lift straight up.
(6) Four different alignment holes are provided on
the plastic ring (Fig. 12).Note that 2.5L and 4.0L
engines have different alignment holes (Fig.
12).
(7) Rotate the distributor shaft and install the pin
punch tool through the proper alignment hole in the
plastic ring (Fig. 12) and into the mating access hole
in the distributor housing. This will prevent the dis-
tributor shaft and rotor from rotating.
(8) Clean the distributor mounting hole area of the
engine block.
(9) Install a new distributor-to-engine block gasket
(Fig. 8).
(10) Install the rotor to the distributor shaft.(11)2.5L 4-Cylinder Engine:Pre-position the dis-
tributor into the engine while holding the centerline
of the base slot in the 1 o'clock position (Fig. 13).
Continue to engage the distributor into the engine.
The rotor and distributor will rotate clockwise during
installation. This is due to the helical cut gears on
the distributor and camshaft. When the distributor is
fully seated to the engine block, the centerline of the
base slot should be aligned to the clamp bolt mount-
ing hole on the engine (Fig. 14). The rotor should
also be pointed slightly past (clockwise of) the 3
o'clock position.
4.0L 6-Cylinder Engine:Pre-position the distrib-
utor into the engine while holding the centerline of
the base slot in the 1 o'clock position (Fig. 13). Con-
tinue to engage the distributor into the engine. The
rotor and distributor will rotate clockwise during in-
stallation. This is due to the helical cut gears on the
distributor and camshaft. When the distributor is
fully seated to the engine block, the centerline of the
base slot should be aligned to the clamp bolt mount-
ing hole on the engine (Fig. 15). The rotor should
also be pointed at the 5 o'clock position.
It may be necessary to rotate the rotor and distrib-
utor shaft (very slightly) to engage the distributor
shaft with the slot in the oil pump gear. The same
may have to be done to engage the distributor gear
with the camshaft gear.
The distributor is correctly installed when:
²the rotor is pointed at the 3 o'clock position (2.5L
engine), or at the 5 o'clock position (4.0L engine).
²the plastic alignment pin (or pin punch tool) is still
installed to distributor.
Fig. 12 Pin Alignment HolesFig. 13 Distributor Pre-positionÐAll Engines
JIGNITION SYSTEMS 8D - 21

motion. Never pull directly on the cable. Internal
damage to cable will result.
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plugs in the Diagnostics/Service Procedures
section of this group.
PLUG CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will re-
main on the spark plug insulator and will cause
plug misfire.
PLUG GAP ADJUSTMENT
Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 20).Never attempt to adjust
the gap by bending the center electrode.
SPARK PLUG GAP
²2.5L 4-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
²4.0L 6-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
PLUG INSTALLATION
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion. This may result
in a change in the spark plug gap, or a cracked por-
celain insulator.
When replacing the spark plug and ignition coil ca-
bles, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise. It could cause cross ignition of the spark plugs,
or short circuit the cables to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Tighten the spark plugs to 35-41 Nzm (26-30 ft.
lbs.) torque.
(3) Install spark plug cables over spark plugs.
SPARK PLUG SECONDARY CABLES
CAUTION: When disconnecting a high voltage cable
from a spark plug or from the distributor cap, twist
the rubber boot slightly (1/2 turn) to break it loose
(Fig. 19). Grasp the boot (not the cable) and pull it
off with a steady, even force.
Install cables into the proper engine cylinder firing
order (Figs. 21 or 22).
When replacing the spark plug and coil cables,
route the cables correctly and secure in the proper
retainers. Failure to route the cables properly can
cause the radio to reproduce ignition noise. It could
also cause cross ignition of the plugs, or short circuit
the cables to ground.
Fig. 19 Cable Removal
Fig. 20 Setting Spark Plug GapÐTypical
8D - 24 IGNITION SYSTEMSJ

IGNITION SWITCHÐXJ MODELS
IGNITION SWITCH AND KEY CYLINDER SERVICE
The ignition switch is located on the steering col-
umn. The Key-In-Switch and Halo Light are integral
with the ignition switch. Refer to Group 8U for Key-
In-Switch and Halo Light diagnosis for XJ models.
Refer to Group 8W, Wiring for ignition switch wir-
ing circuits.
REMOVAL
(1) Disconnect negative battery cable from battery.
(2) If vehicle has a tilt column, remove tilt lever by
turning it counterclockwise.
(3) Remove upper and lower covers from steering
column (Fig. 1).
(4) Remove ignition switch mounting screws. Use
tamper proof torx bit Snap-on TTXR20A2 or equiva-
lent to remove the screws (Fig. 2 or 3).
(5) Gently pull switch away from column. Release
connector locks on 7-terminal wiring connector, then
remove connector from ignition switch.
(6) Release connector lock on 4-terminal connector,
then remove connector from ignition switch (Fig. 4).
(7) To remove key cylinder from ignition switch:
(a) Insert key in ignition switch. Turn key to
LOCK position. Using a TTXR20A2 or equivalent
torx bit, remove key cylinder retaining screw and
bracket (Fig. 5 or 6).
(b) Rotate key clockwise to the OFF position.
Key cylinder will unseat from ignition switch (Fig.
7). When key cylinder is unseated, it will be ap-proximately 1/8 inch away from ignition switch
halo light ring.Do not attempt to remove key
cylinder at this time.
(c) With key cylinder in unseated position, rotate
key counterclockwise to the lock position and re-
move key.
(d) Remove key cylinder from ignition switch
(Fig. 8).
Fig. 1 Shroud Removal/InstallationÐTypical
Fig. 2 Ignition Switch Screw Removal
Fig. 3 Ignition Switch Screw Removal
8D - 26 IGNITION SYSTEMSJ

INSTALLATION
(1) Connect electrical connectors to ignition switch.
Make sure that switch locking tabs are fully seated
in wiring connectors.
(2) Before attaching ignition switch to a tilt steer-
ing column, the transmission shifter must be in Park
position. The park lock dowel pin and column lock
flag must also be properly indexed before installing
switch (Fig. 9).
(a) Place transmission shifter in PARK position.
(b) Place ignition switch in lock position. The
switch is in the lock position when column lock flag
is parallel to ignition switch terminals (Fig. 9).
(c) Position ignition switch park lock dowel pin
so it will engage steering column park lock slider
linkage (Fig. 10).(d) Apply a light coating of grease to column lock
flag and park lock dowel pin.
(3) Place ignition switch against lock housing open-
ing on steering column. Ensure that ignition switch
park lock dowel pin enters slot in park lock slider
linkage in steering column.
(4) Install retaining bracket and ignition switch
mounting screws. Tighten screws to 36.5 Nzm (2664
in. lbs.) torque.
(5) Install ignition lock cylinder:
Fig. 4 Key-In-Switch and Halo Lamp Connector
Fig. 5 Key Cylinder Retaining Screw
Fig. 6 Key Cylinder Retaining Screw
Fig. 7 Unseated Key Cylinder
JIGNITION SYSTEMS 8D - 27

(a) With lock cylinder and ignition switch in
Lock position, insert lock cylinder into ignition
switch until it bottoms.(b) Insert ignition key into lock cylinder. While
gently pushing lock cylinder in toward ignition
switch, rotate ignition key to end of travel.
(6) Install retaining screw into bracket and lock
cylinder. Tighten screw to 36.5 Nzm (2664 in. lbs.)
torque.
(7) Install steering column covers. Tighten screws
to2Nzm (17 in. lbs.) torque.
(8) If vehicle is equipped with a tilt steering col-
umn, install tilt lever.
(9) Connect negative cable to battery.
(10) Check for proper operation of halo light, shift
lock (if applicable), and column lock. Also check for
proper operation of ignition switch accessory, lock,
off, run, and start positions.
Fig. 10 Ignition Switch Mounting PadFig. 8 Key Cylinder Removal
Fig. 9 Ignition Switch View From Column
8D - 28 IGNITION SYSTEMSJ

IGNITION SWITCHÐYJ MODELS
GENERAL INFORMATION
This section will cover the electrical portion
of the ignition switch. To service the mechani-
cal ignition key switch, refer to Group 19,
Steering.
Refer to Group 8W, Wiring for ignition switch wir-
ing circuits.
The ignition switch is mounted under the instru-
ment panel on the lower section of the steering col-
umn. The headlamp dimmer switch is mounted
beside the ignition switch (Fig. 11). Both of these
switches (ignition and dimmer) share the same
mounting screws.
The switch is connected to the ignition key lock as-
sembly by a remote actuator rod. This remote actua-
tor rod fits into an access hole on the bottom of the
ignition switch (Fig. 12).
REMOVAL
(1) Disconnect the negative battery cable at the
battery.
(2) Remove the windshield wiper intermittent con-
trol module and its bracket (if equipped).
(3) Place the ignition key lock in ACCESSORY po-
sition.
(4) Remove the two headlamp dimmer switch at-
taching nuts. Lift the switch from steering column
while disengaging actuator rod.
Before removing dimmer switch, tape the two
remote control actuator rods (ignition switchand dimmer) to the steering column. This will
prevent accidental disengagement from the up-
per part of the steering column.
(5) Remove the ignition switch-to-steering column
attaching screws.
(6) Disengage the ignition switch from the remote
actuator rod by lifting straight up. Remove switch
from steering column.
(7) Remove wiring from switch as follows:
Two electrical connectors are used to connect all
wiring to the ignition switch. One of the connectors is
installed (interlocked) over the top of the other con-
nector. Remove wiring from switch by disconnecting
the (black) harness connector first and then the other
connector. Remove the switch from the vehicle.
SWITCH TESTING
To test the ignition switch circuity and continuity,
proceed as follows. Place the slide bar (on the igni-
tion switch) (Fig. 12) into the detent position to be
tested. An ohmmeter or continuity light may be used
to check switch continuity. Refer to the Ignition
Switch Continuity Tests chart for continuity tests.
Refer to (Fig. 13) for the lettered/numbered terminal
positions.All wiring must be disconnected from
the ignition switch before performing any con-
tinuity testing.
There are five positions on the ignition switch. The
switch positions (in order) are: ACCESSORY, OFF-
LOCK, OFF, ON AND START (Figs. 14 or 15). Each
position has a detent stop (except START), which isFig. 11 Ignition Switch/Headlamp Dimmer SwitchÐ
Typical
Fig. 12 Ignition Switch/Remote Actuator RodÐ
Typical
JIGNITION SYSTEMS 8D - 29

nition switch. Install screws finger tight. Remove the
dimmer switch actuator rod securing-tape from steer-
ing column.
(8) Adjust dimmer switch as follows: Depress the
switch slightly and insert a 3/32-inch drill bit into
the adjustment hole (Fig. 11). This is done to prevent
horizontal switch movement.
(9) Move switch toward steering wheel to remove
any lash from switch actuator rod. Tighten dimmer
and ignition switch fasteners to 4 Nzm (35 in. lbs.)
torque.(10) Install the windshield wiper intermittent con-
trol module and its bracket (if equipped).
(11) Install the negative battery cable.
Test dimmer switch. Test ignition switch operation
in all switch positions. If equipped with a tilt steer-
ing column, test operation of dimmer switch and ig-
nition switch in all tilt positions.
Fig. 14 Detent PositionsÐNon-Tilt Steering Column
Fig. 15 Detent PositionsÐTilt Steering Column
JIGNITION SYSTEMS 8D - 31

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