ignition JEEP CHEROKEE 1994 Service Repair Manual

AUDIO SYSTEMS
CONTENTS
page page
GENERAL INFORMATION.................. 1
RADIO ANTENNA........................ 8XJ SERVICE PROCEDURES................ 4
YJ SERVICE PROCEDURES................ 6
GENERAL INFORMATION
DESCRIPTION
Each radio receives ignition feed from an ignition
switch controlled fuse. There is an additional in-line
fuse in the back of the radio chassis. The in-line fuse
will blow in the event an internal short occurs.
The electronically tuned radio (ETR)/cassette
models protect the vehicle from a radio failure
with an in-line fuse located in the rear of the ra-
dio chassis (Fig. 1).
XJ/YJ vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed when the vehicles
are shipped from the factory. This fuse is in the
Power Distribution Center to prevent battery dis-
charge during storage. For specific location refer to
Group 8W - Wiring Diagrams.
The IOD fuse is in the radio memory circuitry and
should be checked if the memory (time or radio sta-
tion programming) is inoperative.
All radios are connected to the radio illumination
relay. When the ignition switch is in ON or ACCES-
SORY and the radio illumination relay remains de-
energized, the radio receives battery voltage via the
relay from the:
²(20 amp #7 fuse YJ)
²(15 amp #2 fuse XJ).
The radio illumination relay is energized when the
headlamp switch is used to turn on the parklamps or
headlamps. Battery voltage is switched to the dimdisplay input of the radio through the relay contacts.
The radio panel illumination is dimmed for night
driving.
The ETR models require an additional battery feed
connection to the (10 amp #F16 fuse-YJ), (10 amp
#9 fuse-XJ) to retain the radio's memory when the
ignition switch is turned OFF.
ETR models are self-compensating. A radio
trimmer adjustment is not required.
DIAGNOSIS
RADIO INOPERATIVE
Turn ignition switch to ON
²Inspect the (#7-YJ), (#2-XJ) fuse and replace if
necessary.
²Measure voltage at battery side of the fuse. There
should be 12 volts. If not, repair open from ignition
switch.
²Inspect in-line fuse at rear of radio and replace if
necessary.
Turn ignition switch to OFF.
²Disconnect radio connector. Measure resistance
from radio ground pin to a clean chassis ground.
There should be zero ohms. If not, repair open be-
tween radio connector and ground.
NO AUDIO OUTPUT ON ONE OR MORE
SPEAKERS
Refer to Radio Connector Pins.
FRONT SPEAKERS
²Radio OFF, radio connector disconnected. Measure
resistance between radio left front feed and return
connector pins. Measure between right front feed and
return connector pins. The meter should read 5 to 8
ohms. If the meter reading is correct, remove radio
for service. If not, repair wiring or replace speakers
as required.
Fig. 1 In-Line Fuse Location
JAUDIO SYSTEMS 8F - 1

REAR SPEAKERS
²Radio OFF, radio connector disconnected. Measure
resistance between radio left rear feed and return
connector pins. Measure between right rear feed and
return connector pins. The meter should read 5 to 8
ohms. If meter reading is correct remove radio for
service. If not, repair wiring or replace speakers as
required.
DISTORTED AUDIO OUTPUT ON ONE OR
MORE SPEAKERS
²With the radio ON, substitute known good speaker
or speakers. If the sound is still distorted, remove ra-
dio for service.
WEAK OR NO RECEPTION; NO AUDIO
OUTPUT; BACKGROUND NOISE PRESENT
Ignition switch in ON, radio ON.
²Inspect antenna cable and connector at radio and
tighten or repair as necessary.
²Unplug coax cable and connectors from radio. Mea-
sure resistance from center conductor to coaxial
shield. The meter should read infinite resistance
(open). If it does not, replace antenna assembly.
²Measure resistance of antenna mast to tip of cen-
ter conductor at radio end of cable. The meter should
read 0 to 0.5 ohms. If it does not, replace lead-in ca-
ble or antenna assembly.
²Measure resistance from coaxial shield to chassis
ground (vehicle body). The meter should read zero
ohms. If it does not, ground antenna base to vehicle
body, or replace antenna assembly as required
For all problems with no or low audio output
not resolved by these tests, remove radio for ser-
vice.
MEMORY DOES NOT OPERATE
²Inspect (F16 in Power Distribution Center-YJ),
(#9 in Fuse Panel-XJ) fuse and replace if necessary.
²Measure voltage at battery side of previously ref-
erenced fuse. There should be 12 volts at battery side
of fuse. If not, check the Maxi fuse.
Refer to Group 8W - Wiring Diagrams.
²Measure voltage at radio connector pin 4. There
should be 12 volts. If meter reading is correct, re-
move radio for service. If not, repair open from fuse.
RADIO DISPLAY ILLUMINATION (PARKLAMPS
AND HEADLAMPS OPERATING NORMALLY)
Headlamp switch OFF, radio ON.
²Measure voltage at radio connector pin 10. There
should be 12 volts. If not, go to next step. If OK, re-
move radio for repair by authorized outlet.
²Measure voltage at illumination relay pin 3. There
should be 12 volts. If 12 volts present, replace illumi-
nation relay. If not, repair open in circuit.RADIO DISPLAY ILLUMINATION DIMMING CIRCUIT
Turn headlamp switch to PARKLAMPS for
voltage tests; turn headlamp switch to OFF for
resistance tests.
²Separate relay connector from radio illumination
relay. Measure resistance from relay connector pin 2
to a clean chassis ground. The meter should read
zero ohms. If not, repair open between relay connec-
tor and ground.
²Measure voltage at radio illumination relay pin 5.
There should be battery voltage. If not repair open
from headlamp switch.
²Measure voltage at radio illumination relay pin 4.
Voltage should vary with dimmer switch. If OK, go
to next step. If not, repair open circuit between pin 4
and interior lamp rheostat.
²Measure voltage at radio illumination relay pin
10. Voltage should vary with dimmer switch. If OK,
remove radio for repair by authorized outlet. If not,
replace radio illumination relay.NOISE INTERFERENCE CHANGES WITH
ENGINE SPEED
²Inspect connections at: generator, ignition module,
antenna coaxial ground, radio ground, body to engine
block ground (braided ground strap). Repair as re-
quired.
RADIO NOISE DIAGNOSIS
8F - 2 AUDIO SYSTEMSJ

²Inspect secondary ignition system components:
wire routing and condition, distributor cap and rotor,
ignition coil, spark plugs. Reroute or replace as re-
quired.RADIO ILLUMINATION RELAY
XJ
The radio illumination relay is in the relay center.
The relay center is located on the lower instrument
panel trim cover, right of the steering column
(Fig. 2).
YJ
The radio illumination relay is taped to the har-
ness above the radio.
RADIO CONNECTOR PINS
Fig. 2 Radio Illumination Relay
JAUDIO SYSTEMS 8F - 3

VEHICLE SPEED CONTROL SYSTEM
CONTENTS
page page
SERVICE PROCEDURES................... 9TEST PROCEDURES...................... 5
GENERAL INFORMATION
The vehicle speed control system (Fig. 1) is electri-
cally actuated and vacuum operated. The turn signal
lever on the steering column incorporates a slide
switch that has three positions OFF, ON or RE-
SUME. A SET button is in the end of the lever. This
device is designed to operate at speeds above approx-
imately 35 mph.
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.TO ACTIVATE:Put ON/OFF switch in ON posi-
tion. When the desired speed is achieved, push and
release the SET button to turn on and engage the
system. Remove foot from accelerator. Speed will be
maintained at this level.
TO DEACTIVATE:A soft tap of the brake pedal,
normal brake application or depressing the clutch
pedal while the system is engaged will disengage
speed control without erasing memory. A sudden in-
crease in engine speed may be experienced if the
clutch pedal is depressed while the speed control sys-
tem is engaged. Moving the slide switch to the OFF
position or turning the ignition OFF also disengages
the system and in addition erases the memory.
Fig. 1 Speed Control System
JVEHICLE SPEED CONTROL SYSTEM 8H - 1

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

ELECTRICAL TESTS AT POWERTRAIN CONTROL
MODULE
(1) Unplug 60-way connector from Powertrain Con-
trol Module, located on drivers side fender (Fig. 4).
(2) Connect negative lead of voltmeter to a good
body ground near module.
(3) For the following tests, ignition switch must be
in ON position. Refer to Fig. 5 for controller terminal
locations. Touch positive lead of voltmeter to termi-
nal in cavity number 33. With speed control switch
in OFF position, voltmeter should read 0 volts. With
speed control switch in ON position, voltmeter should
read battery voltage. If not, repair main harness as
necessary.(4) Touch positive lead of the voltmeter to terminal
in cavity number 53. As in step (3), voltmeter should
read 0 volts with switch in OFF position and battery
voltage with switch in ON position.
(5) Touch positive lead of voltmeter to terminal in
cavity number 48. With speed control switch in OFF
position, voltmeter should read 0 volts. With switch
in ON position, voltmeter should read battery volt-
age. Pressing SET button should cause voltmeter to
change from battery voltage to 0 volts for as long as
the switch is held. If not, perform the speed control
switch test. If the switch is not at fault, then check
main harness and repair as necessary.
(6) Touch positive lead of voltmeter to terminal in
cavity number 50. The voltmeter should read 0 volts
with speed control switch in either OFF or ON posi-
tion. With switch in either RESUME or SET posi-
tion, voltmeter should read battery voltage. If not,
perform the speed control switch test. If the switch is
not at fault, then check main harness and repair as
necessary.
(7) Touch positive lead of voltmeter to terminal in
cavity number 49. The voltmeter should read 0 volts
with switch in OFF position. With switch in ON po-
sition, voltmeter should read battery voltage. The
voltmeter will continue to read battery voltage when
either the SET or RESUME switch is pressed. If not,
Fig. 2 Servo And Harness ConnectorÐLeft Hand
Drive
Fig. 3 Servo And Harness ConnectorÐRight Hand
Drive
Fig. 4 Powertrain Control Module and Connector
Location
Fig. 5 Powertrain Control Module 60-Way Connector
Shown from Terminal End
8H - 6 VEHICLE SPEED CONTROL SYSTEMJ

SERVICE PROCEDURES
INDEX
page page
Servo Cable Replacement................... 9
Speed Control Servo Replacement............ 9Speed Control Switch Replacement............ 9
SPEED CONTROL SERVO REPLACEMENT
REMOVAL
(1) Disconnect vacuum hose at servo (Figs. 1 and
2).
(2) Disconnect electrical connector at servo.
(3) Remove 2 nuts from cable sleeve.
(4) Pull speed control cable away from servo to ex-
pose cable retaining clip.
(5) Remove clip attaching cable to servo.
(6) Pull servo away from mounting bracket.
INSTALLATION
(1) Insert servo studs through holes in servo
mounting bracket.
(2) With throttle blocked to full open position,
align hole in cable sleeve with hole in servo pin and
install retaining clip.
(3)
Insert servo studs through holes in cable sleeve.
(4) Install 2 attaching nuts and tighten to 6 Nzm
(50 in. lbs.).
(5) Connect vacuum hose to servo.
(6) Connect electrical connector to servo terminals.
SERVO CABLE REPLACEMENT
CAUTION: Use finger pressure only to remove the
speed control cable connector at the bell crank. Pli-
ers or screwdriver can break connector requiring
complete cable replacement.
(1) Using finger pressure only, remove speed con-
trol cable connector at bell crank by pushing connec-
tor off the bell crank (Fig. 3). DO NOT try to pull
connector off perpendicular to the bell crank.
(2) Squeeze tabs on speed control cable and push
out of locking plate (Fig. 4).
(3) Pull cable out of cable guide.
(4) Remove 2 nuts and cable housing from servo.
(5) Release cable clip from servo cable and remove
servo cable.
(6) To install, reverse the removal procedure.
SPEED CONTROL SWITCH REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove horn button with a push and turn mo-
tion.
(3) Remove horn button components (Fig. 5).
(4) Turn ignition switch to LOCK position and re-
move steering wheel nut and washer.
(5) Scribe an alignment mark on the steering in
line with the mark already existing on the end of the
steering column.
Fig. 2 Speed Control ServoÐRight Hand Drive
Fig. 1 Speed Control ServoÐLeft Hand Drive
JVEHICLE SPEED CONTROL SYSTEM 8H - 9

(6) Remove vibration damper from the steering col-
umn hub, if equipped.(7) Remove steering wheel using a steering wheel
puller.
WARNING: TO REMOVE THE STEERING SHAFT
SNAP RING IN THE FOLLOWING STEP, THE LOCK-
PLATE MUST BE COMPRESSED. DO NOT ATTEMPT
TO REMOVE THE LOCKPLATE WITHOUT COM-
PRESSOR TOOL C4156 AS THE LOCKPLATE IS UN-
DER HEAVY SPRING TENSION.
(8) Compress lockplate with compressor tool
C4156.
(9) Remove steering shaft snap ring (Fig. 6). Dis-
card snap ring. It is not reusable.
(10) Remove compressor tool.
(11) Remove lockplate, cancelling cam, and upper
bearing preload spring.
(12) Remove horn button components from cancel-
ing cam.
(13) Remove screw and hazard warning switch
knob.
(14) Remove actuator arm attaching screw.
(15) Remove turn signal switch attaching screws.
(16) Unplug speed control switch connector.
(17) Pull speed control harness out of the column.
(18) Insert ignition key in lock cylinder and turn
key to ON position.
(19) Remove key warning buzzer switch and re-
taining clip with a paper clip inserted below retainer
so that retainer is flattened (Fig. 7).
Do not attempt to remove buzzer switch and
clip separately. The clip could fall into the col-
umn jacket.
Fig. 3 Remove Bell Crank Connector
Fig. 4 Remove/Install Speed Control Cable to
Locking Plate
Fig. 5 Steering Wheel Removal/Installation
8H - 10 VEHICLE SPEED CONTROL SYSTEMJ

(20) Remove ignition lock cylinder retaining screw
and pull lock cylinder out of column housing (Fig. 8).
(21) Remove screws that attach housing and
shroud assembly to column jacket and carefully re-
move housing and shroud assembly (Fig. 9).
Do not let dimmer switch rod, lock pin or lock
rack fall out.
(22) Remove turn signal/wiper lever by pulling it
straight out of column.(23) Remove wiper switch cover from back of hous-
ing and shroud assembly (Fig. 10). If equipped with
column shift, remove screw holding the cover on.
(24) Remove pivot screw from housing and remove
wiper switch.
(25) Install a new switch and switch cover.
(26) Push on dimmer switch rod to make sure it is
connected then carefully position housing and shroud
assembly to column (Fig. 11).
Fig. 6 Lockplate Removal
Fig. 7 Buzzer Switch Removal
Fig. 8 Lock Cylinder Removal/Installation
Fig. 9 Steering Column Housing
Removal/Installation
JVEHICLE SPEED CONTROL SYSTEM 8H - 11

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