1994 JEEP CHEROKEE instrument cluster

INSTRUMENT CLUSTER
JYJ INSTRUMENT PANEL AND GAUGES 8E - 15

DIAGNOSINGÐALL LAMPS OUT
(1) Inspect fuse #9. Replace as required.
(2) Measure voltage at instrument cluster connec-
tor terminal 20. Meter should read zero ohms. If not,
repair open to ground.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. The lamp is con-
trolled by the 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 shifted
into another gear.
The indicator lamp is normally illuminated when
the ignition switch is turned ON and it is turned off
when the engine is started. The lamp will be lighted
during engine operation according to engine speed
and load.
(1) Turn ignition switch to ON.
(2) Ground pin 2 of cluster connector. Lamp should
light. If not, replace bulb. If OK, continue with step 3.
(3) Turn ignition switch to OFF. Check for conti-
nuity between cluster connector pin 2 and pin 54 of
the PCM. If not, repair open. If OK, refer to DRB
scan tool actuator test of upshift indicator.
BRAKE INDICATOR LAMP
The brake indicator is a dual function lamp. It will in-
dicate an unequal pressure condition in the split brake
hydraulic system and it also will indicate when the park-
ing brake is engaged. Separate switches are used for each
indicator lamp function. A switch mounted on the brake
pedal assembly will close a ground circuit whenever the
parking brakes are applied. A second switch is installed
in the brake hydraulic lines near the master cylinder. If
the switch is balanced by equal pressure on both ends of
the switch valve, the valve remains centered and the
lamp remains off. If the valve is shifted by unequal pres-
sure between the front or rear brake hydraulic systems,
the lamp circuit is connected to ground. To make sure
the brake lamp is functional before the vehicle is driven,
it is illuminated through a ground circuit when the igni-
tion switch is turned to the START position.
(1) Turn ignition switch to ON.
(2) Ground pin 1 of the cluster connector. Lamp
should light. If not, replace bulb. If OK, continue
with step 3.
(3) Turn ignition switch to OFF. Check for continuity to
park brake switch and brake warning switch.
MALFUNCTION INDICATOR LAMP (CHECK ENGINE)
The Malfunction Indicator Lamp (Check Engine) il-
luminates each time the ignition switch is turned
ON and stays on for 3 seconds as a bulb test.If the PCM receives an incorrect signal or no signal
from certain sensors or emission related systems the
lamp is turned on (pin 32 of PCM). This is a warning
that the PCM has recorded a system or sensor mal-
function. In some cases when a diagnostic fault is de-
clared the PCM will go into a limp-in mode in an
attempt to keep the system operating. It signals an
immediate need for service.
The lamp also can be used to display diagnostic
trouble codes (DTC). Cycle the ignition switch ON,
OFF, ON, OFF, ON within 5 seconds. This will allow
any DTC's stored in the PCM memory to be dis-
played in a series of flashes representing digits.
(1) Turn ignition switch to ON.
(2) Ground pin 4 of cluster connector. Lamp should
light. If not, replace bulb. If OK, continue with step 3.
(3) Turn ignition switch to OFF. Check for conti-
nuity between cluster connector pin 4 and PCM cav-
ity 32. If OK, replace PCM. If not, repair open.
SEAT BELT REMINDER LAMP
Apply 12 volts to terminal 16 of cluster connector.
Lamp should light. If not, replace bulb. If OK, check
wiring for an open to buzzer module. Refer to Group
8U - Chime/Buzzer Warning Systems.
INSTRUMENT PANEL ILLUMINATION LAMPS
The instrument panel illumination lamps share
two common connections. There is a splice after fuse
#10 that connects the lamps to battery feed. There is
also a splice that connects all lamps to ground. Be-
cause they share these common connection points in
a parallel circuit, the illumination lamps will all
come on at the same time. It also means one or more
lamps can be out without affecting the operation of
the other lamps.
On the battery side of the circuit, the headlamp
switch illumination rheostat/switch and panel lamps
fuse receive battery feed in series from the park/tail
fuse. In the park lamp position, the headlamp switch
completes the circuit from the park/tail fuse to the il-
lumination rheostat/switch and panel lamps fuse.
The illumination rheostat contains a variable resis-
tor that allows the driver to vary illumination inten-
sity from off to full brightness.
DIAGNOSIS
(1) Turn parking lamps ON.
(2) Check fuse #10. Replace as required.
(3) Measure voltage at battery side of fuse #10
with rheostat turned counterclockwise to clockwise
(LO to HI). Meter should read zero volts to battery
voltage. If not, replace headlamp switch.
(4) Measure resistance at ground side of fuse #10
with parking lamps OFF. Meter should read almost
zero ohms (except bulb filament). If not, repair open
to ground. If zero ohms, 12 volt supply wire from fuse
is shorted to ground, repair short.
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INSTRUMENT CLUSTER SERVICE PROCEDURES
INDEX
page page
Headlamp Switch/Illumination Rheostat........ 21
Indicator Bezel Replacement................ 17
Instrument Cluster Bulb Replacement......... 19
Instrument Cluster Replacement............. 17Printed Circuit Replacement................ 19
Rear Defogger/Fog Lamp/Rear Wiper Switches . . 21
Speedometer Replacement................. 17
Tachometer Replacement.................. 17
INSTRUMENT CLUSTER REPLACEMENT
(1) Remove 6 shroud screws (Fig. 1).
(2) Slide shroud toward steering wheel.
(3) Remove 3 screws holding right side switch
panel (Fig. 2).
(4) Remove 3 screws holding left side switch bezel.(5) Remove 2 screws holding cluster in place.
(6) Lift up top of cluster. Roll cluster out between
steering column and instrument panel far enough to
reach connector located behind tachometer.
(7) Disconnect cluster connector and remove clus-
ter (Fig. 3).
(8) To install cluster, reverse the removal proce-
dures.
TACHOMETER REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrumentation shroud (Fig. 1). Refer
to Instrument Cluster Replacement.
(3) Remove cluster as described in Instrument
Cluster replacement.
(4) Remove 3 screws and tachometer lens (Fig. 4).
(5) Gently pry up clip to release lens from bezel
(Fig. 5).
(6) Remove 3 screws from rear of housing (Fig. 6).
Remove tachometer.
(7) Install tachometer with 3 screws.
(8) Snap lens into place.
(9) Install lens with 3 screws.
(10) To install the cluster, reverse the removal pro-
cedures.
SPEEDOMETER REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrument shroud (Fig. 1). Refer to In-
strument Cluster Replacement.
(3) Remove cluster as described in Instrument
Cluster Replacement.
(4) Remove 3 screws and speedometer lens (Fig. 7).
(5) Gently pry up clip to release lens from bezel
(Fig. 5).
(6) Remove 3 screws from rear of housing (Fig. 8).
Remove speedometer.
(7) Install speedometer with 3 screws.
(8) Snap lens into place.
(9) Install lens with 3 screws.
(10) To install the cluster, reverse the removal pro-
cedures.
INDICATOR BEZEL REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrumentation shroud (Fig. 1).
(3) Remove 3 screws and tachometer lens (Fig. 4).
Fig. 2 Cluster Removal
Fig. 1 Instrument Shroud Removal/Installation
JYJ INSTRUMENT PANEL AND GAUGES 8E - 17

Fig. 3 Instrument Cluster
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(4) Gently pry up clip to release lens from bezel
(Fig. 5).
(5) Remove 3 screws and speedometer lens (Fig. 7).
(6) Gently pry up clip to release lens from bezel
(Fig. 5).
(7) Remove indicator bezel (Fig. 3).
(8) Lift indicator panel off locating pins.
(9) Reverse removal procedures to install new
panel and bezel.
(10) Install speedometer and tachometer lenses.
(11) Install shroud.(12) Install negative cable to battery.INSTRUMENT CLUSTER BULB REPLACEMENT
Refer to Printed Circuit Replacement for bulb re-
placement.
PRINTED CIRCUIT REPLACEMENT
Remove cluster as described in cluster replacement.
DISASSEMBLY
(1) Remove all attaching screws for speedometer
and tachometer (Fig. 9).
Fig. 4 Tachometer Lens
Fig. 5 Cluster Lens Retaining Clip
Fig. 6 Tachometer Removal/Installation
Fig. 7 Speedometer Lens
JYJ INSTRUMENT PANEL AND GAUGES 8E - 19

(2) Remove 2 screws holding cluster connector re-
taining plate to housing (Fig. 10).
(3) To remove plate, slide it toward bottom of hous-
ing (Fig. 11).
(4) Remove lamp sockets from circuit board.(5) Remove printed circuit including connector.
ASSEMBLY
(1) Position printed circuit, including connector, on
the back of instrument panel cluster.
Fig. 8 Speedometer Removal/Installation
Fig. 9 Printed Circuit Removal/Installation
Fig. 10 Printed Circuit Connector Attaching Screws
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(2) Remove gauge bezel and lens.
(3) Hold components in place and install screws.
(4) Install lamp sockets.
(5) Pivot connector up and install retaining plate.
(6) Install gauge bezel and cluster lens.
HEADLAMP SWITCH/ILLUMINATION RHEOSTAT
(1) Disconnect negative cable from battery.
(2) Remove instrument cluster shroud (Fig. 1).
(3) Remove 3 screws holding switch bezel (Fig. 12).
(4) Remove 2 screws from the appropriate switch
to be replaced (Fig. 13).
(5) Remove the switch connector.
(6) Reverse the removal procedures for installa-
tion.
REAR DEFOGGER/FOG LAMP/REAR WIPER
SWITCHES
(1) Disconnect negative cable from battery.
(2) Remove instrument cluster shroud (Fig. 1).
(3) Remove 3 screws holding switch bezel (Fig. 14).
(4) Remove the switch connector.
(5) Release tabs holding switch and remove switch.
(6) Reverse the removal procedures for installa-
tion.
Fig. 11 Cluster Connector Retaining Strap
Fig. 12 Left Hand Instrument Panel Switch Bezel.
Fig. 13 Headlamp Switch/Illumination Rheostat
Fig. 14 Right Hand Instrument Panel Switch Bezel
JYJ INSTRUMENT PANEL AND GAUGES 8E - 21

GAUGE PACKAGE GENERAL INFORMATION
The gauge package contains 4 gauges and the 4
wheel drive indicator. The gauges have a common
battery feed from fuse #9 and ignition switch. Al-
though they have separate power sources, the 4
gauges share a common ground connection.
The voltmeter indicates electrical system voltage.
When the engine is not running, the voltage regis-
tered is from the battery. After the engine is started,
charging system voltage is indicated. In the gauge
package, the voltmeter forms a parallel connectionacross the battery feed and ground.
The remaining gauges - oil pressure, fuel and cool-
ant temperature - are connected to individual sender
units. Variable resistors in the senders will change
the amount of current allowed to flow through the
gauge coils. As current flow through the coils varies,
the position of the indicator needle also will vary.
The 4 gauges are connected to battery feed, ground
and the sender units through a printed circuit
mounted on the back of the gauge housing.
GAUGE PACKAGE DIAGNOSIS
ALL GAUGES INOPERATIVE (Fig. 15)
(1) Check the fuse #9. Replace as required.
(2) Turn ignition switch to ON and measure volt-
age at battery side of fuse #9. Meter should read bat-
tery voltage. If not, repair open from ignition switch.
(3) Unplug gauge package connector from gauge
package.
(4) Turn ignition switch to OFF and measure resis-
tance from instrument cluster connector terminals 1
and 13 to a clean chassis ground. Meter should read
zero ohms. If not, repair open to ground.
(5) Turn ignition switch to ON and measure volt-
age at instrument cluster connector terminals 2 and
12. Meter should read battery voltage. If not, repair
open from fuse panel.
ONE GAUGE INOPERATIVE
Does not apply to voltmeter.
OIL PRESSURE SENDER
(1) Turn ignition switch to ON.
(2) Unplug oil pressure sender connector from oil
pressure sender.
(3) Touch connector to engine block (ground).
Gauge should read at low end of scale.
(4) When connector is NOT touching ground (open
circuit) gauge should read at high end of scale. If OK
replace sender. If not, proceed with step 5.
(5) Check circuit between sender and gauge for an
open. Repair as required. If wiring is OK, replace
gauge.
COOLANT TEMPERATURE SENDER
(1) Turn ignition switch to ON.
(2) Unplug coolant temperature sender connector
from coolant temperature sender.
(3) Touch connector to engine block (ground).
Gauge should read at high end of scale.
(4) When connector is NOT touching ground (open
circuit) gauge should read at low end of scale. If OK
replace sender. If not, proceed with step 5.
(5) Check circuit between sender and gauge for an
open. Repair as required. If wiring is OK, replace
gauge.
FUEL GAUGE SENDER
(1) Turn ignition switch to ON.
(2) Separate fuel gauge sender connector from fuel
gauge sender near tank.
(3) Ground the center wire of the body harness
side of the connector. The gauge should read at low
end of scale. If OK, check sending unit (step 4). If
not, check circuit between connector and gauge. Re-
pair as required. If circuit is OK, replace gauge.
(4) Turn ignition switch to OFF.
(5) Measure resistance from fuel gauge sender con-
nector center terminal to a clean chassis ground.
Meter readings should correspond to those shown in
Specifications. If not OK, replace sender. If OK, re-
pair open from fuel gauge sender connector to
ground.
PRINTED CIRCUIT
(1) Turn ignition switch to ON.
(2) Unplug gauge package connector from gauge
package.
(3) Measure resistance from gauge package termi-
nal 12 (fuel and coolant temperature gauge) or from
terminal 2 (voltmeter and oil pressure gauge) to
gauge battery terminal. Meter should read zero
ohms. If not, replace/repair printed circuit.
(4) Measure resistance from gauge package termi-
nal 13 (fuel and coolant temperature gauge) or from
terminal 1 (voltmeter and oil pressure gauge) to
gauge ground terminal. Meter should read zero
ohms. If not, replace/repair printed circuit. If zero
ohms, replace gauge.
GAUGE CALIBRATION VALUES
Use the charts in Specifications. The calibration of
the gauge can be checked. If the indicator needle is
not in the correct position, replace the gauge.
4WD INDICATOR
The four-wheel drive indicator lamp circuit is com-
pleted by the Command-Trac switch located below
the battery.
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