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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

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

TURN SIGNALSÐYJ
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
²front side marker bulb
With the headlamps OFF, the turn and side
marker lamps flash in unison.With the headlamps
ON, the turn and side marker lamps flash alter-
nately.
DIAGNOSINGÐTURN 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) Locate fuse block under driver's side of instru-
ment panel.(3) Remove and inspect 15 amp #4 fuse. Replace if
necessary. If OK, go to next step.
(4) Remove turn flasher, light blue can, located in
fuse block.
(5) Turn ignition switch to ACCESSORY. Check
for battery voltage at cavity on left (closest to hazard
flasher can). If OK, go to next step. If not, repair
open circuit in wiring between turn flasher and #4
fuse.
(6) 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.
(7) Turn ignition switch to OFF. Follow procedure
for turn/hazard switch replacement to locate steering
column connector. Unplug connector.
(8) Turn ignition switch to ACCESSORY. Check
for battery voltage at connector terminal L. If OK,
replace turn/hazard switch. If not, repair open circuit
in wiring between turn flasher and steering column
connector terminal L.
HAZARD LAMPSÐYJ
Refer to Section 8W - Wiring Diagrams for cir-
cuit wiring diagram.
DESCRIPTION
With the hazard switch ON, current flows through
the:
²hazard flasher
²turn/hazard switch
²two front turn signal bulbs
²two rear turn signal bulbs
²two front side marker bulbs
²two turn indicator bulbs.
All of these bulbs will flash on and off.
DIAGNOSISÐHAZARD LAMPS INOPERATIVE
(1) Inspect 20 amp #F5 fuse in Power Distribution
Center (PDC). The PDC is located in the engine com-
partment, 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 left. If OK, go to next step. If not, repair open cir-
cuit in wiring between #F5 fuse and hazard flasher
left 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.
8J - 2 TURN SIGNALS AND HAZARD WARNING FLASHERJ

A blue wire (without a connector) located under in-
strument panel near fuse panel is available for
trailer electric brake control unit.
The stop lamp and turn signal plug-in relays are
located behind left quarter trim panel.
HITCH REMOVALÐXJ VEHICLES
An XJ class III, weight-distributing/equalizer type
hitch is comprised of:
²a towing tube with a ball mount receptacle, and²various reinforcement/support brackets that are at-
tached to the vehicle frame sills and rear crossmem-
ber with bolts.
(1) If necessary, remove the trailer tow wire har-
ness connector from the hitch.
(2) Support the hitch.
(3) Remove the bolts that attach the towing tube
to the frame sills and reinforcement bracket. If
equipped, remove the fuel tank skid plate.
Fig. 14 Equalizer Type HitchÐXJ Vehicles
Fig. 12 Class III Trailer Tow Wire Harness and
ConnectorsFig. 13 Class III Trailer Tow Wire Harness Plug-In
Relays
JBODY COMPONENTSÐXJ VEHICLES 23 - 89

The three compounds can be identified with a
flame test (Fig. 15). To perform the test, first cut a
small sample of the material from a non-visible por-
tion of the plastic. Then apply an open flame to the
sample and observe the smoke or flame color.
ABS and polypropylene only require an open flame
for testing. However, vinyl must be burned in combi-
nation with copper.
To test vinyl, heat a length of solid copper wire un-
til it is red hot. Immediately apply the hot wire to
the plastic sample until some of the material adheres
to the copper. Then expose the copper wire and sam-
ple to an open flame (Fig. 15).
²ABS material will produce black smoke when
burned.
²Polypropylene will produce little or no smoke.
²Vinyl will produce a blue green flame when
burned in combination with copper.
EXTERIOR BODY COLORS
Exterior vehicle body colors are identified on the
Vehicle Code plate. The plate is located on the left
side of the dash panel in the engine compartment.
The color code location is described in the Introduc-
tion of this manual.
OEM paint colors are generally available from all
of the major paint suppliers. They are supplied in the
form of either mixing formulas or factory packaged
(pre-mixed) paint.
The exterior body and interior trim colors and cor-
responding JeepŸ paint codes are listed in the fol-
lowing charts.
Fig. 15 Plastic Flame Tests
Fig. 13 Underbody Center Section UndercoatÐXJ
Vehicles
Fig. 14 Underbody Rear Section (Above Fuel Tank)
UndercoatÐXJ Vehicles
23 - 204 BODY COMPONENTSÐXJ VEHICLESJ

(2) Close all the hand valves.
(3) Connect the red charging hose to the discharge
service valve.
(4) Connect the blue charging hose to the inlet
(suction) service valve.
(5) Discharge the system. Leave the suction and
discharge service valves in the mid-position.
CAUTION: The system must be completely dis-
charged into a recovery device before evacuating. If
the system is still charged, refrigerant can enter
and damage the vacuum pump.
(6) Connect the vacuum pump hose to the vacuum
pump inlet.
(7) Open the low and high pressure control valves
on the charging station.
(8) Start the vacuum pump. Open the vacuum con-
trol valve and note the vacuum reading.
(9) Test the system for leaks as follows:
²Close the manifold hand valves.
²Stop the vacuum pump and observe the vacuum
reading.
²If the system is leak-free, vacuum will hold steady
at the level indicated when the pump was stopped. If
vacuum remains steady for 3-5 minutes, resume and
continue evacuation for a minimum of 30 minutes.
²If the system has a leak, vacuum will fall off or
rapidly drop to a 0 reading. If a leak exists, partially
charge the system. Find and repair the leak and re-
sume evacuation.
(10) Continue evacuating the system for a mini-
mum of 30 minutes after attaining the lowest vac-
uum level.
(11) Fill the station charging cylinder while the
system is evacuating.
(12) Close the vacuum control valve and stop the
vacuum pump.
(13) Observe low pressure gauge to determine if a
system leak exists. If the system is leak-free, the sys-
tem is now ready for charging.
SYSTEM CHARGE
CHARGE CAPACITY
The recommended system charge is 1.1 kg (38 oz.)
of R-12 refrigerant for XJ vehicles and 0.9 kg (32 oz.)
for YJ vehicles.
Add an additional 28 grams (1 fluid oz.) of
compressor oil to the system when a hose, re-
ceiver-drier, condenser, expansion valve or
evaporator core is replaced.
PORTABLE SERVICE STATION
(1) Fill the station charging cylinder. Refrigerant
should be observed rising in the cylinder sight glass.
(2) Slightly open the valve at the top of the cylin-
der when pressure in the charging cylinder and re-frigerant supply tank are equal. This relieves head
pressure allowing refrigerant to continue filling the
cylinder.
(3) Observe the pressure gauge at the top of the
cylinder. Rotate the plastic cover on the cylinder un-
til the pressure heading column corresponds with the
gauge pressure in-line with the sight glass.
FOR EXAMPLE:ÐThe pressure gauge at the top
of the cylinder indicates 483 kPa (70 psi). Locate the
column with the pressure heading of 483 (70) and ro-
tate the cover so the 483 (70) column aligns with the
sight glass.
(4) When refrigerant reaches the correct level in
the sight glass, close the right hand valve at cylinder
base and on the refrigerant drum.
(5) Close the valve at the top of the charging cyl-
inder.
(6) Check for bubbles in the refrigerant using the
cylinder sight glass. If bubbles appear in the refrig-
erant, tilt the charging station rearward momen-
tarily.
(7) Connect the heating element cord to the power
pack receptacle and turn the heater switch ON.
(8) Allow the refrigerant to warm for about 10
minutes while the vacuum pump is operating.
WARNING: WEAR GOGGLES TO PROTECT THE
EYES.
(9) Discharge and evacuate the system.
(10) Close the low pressure valve on the charging
station.
(11) Fully open the left hand refrigerant control
valve at the base of the cylinder and the high pres-
sure valve on the charging station.
(12) Charge the system.
(13) Close the refrigerant control valve and the
high pressure valve on the charging station.
CAUTION: DO NOT permit the liquid level to drop
below 0 on the cylinder sight glass.
(14) Close the manifold gauges after completion of
the charging operation and check the high and low
side pressures.
(15) Check system operation.
CAUTION: DO NOT check system pressures until
the high and low pressure valves on the charging
station are closed. The low pressure gauge could
be damaged if the valves are open.
(16) Close all the valves on the charging station
and close the refrigerant drum valve when all the op-
erations are completed.
(17) Back-seat the service valves by turning them
fully counterclockwise. Install the quick seal caps on
the valves afterward.
JHEATING AND AIR CONDITIONING 24 - 5

AIR CONDITIONING EQUIPMENT
WARNING: EYE PROTECTION MUST BE USED
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE PROCEEDING WITH THIS OPERATION.
PERSONNEL INJURY CAN RESULT.
When servicing an air conditioning system, a
R-134a Charging Station and a Recovery/Recycling
Station is required. These devices must meet SAE
standard J2210. Refer to the operating instructions
provided with the equipment for proper operation.
A manifold gauge set (Fig. 1) must also be used
with the Charging and or Recovery/Recycling Station.
The service hoses on the gauge set uses a Quick-Dis-
connect coupler. The coupler has a knob on top which
is used to engage and disengage the sharder valve in
the service port.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: DO NOT use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
CENTER GAUGE HOSE
The center hose is YELLOW or WHITE with
BLACK STRIP. It is used to recover, evacuate and
charge the refrigerant system. When the low or high
pressure gauge valves on the manifold gauge set are
opened, the refrigerant in the system will escape
through this hose.
This hose attaches to the Recovery/Recycling sta-
tion. Refer to the Recovery/Recycling station Opera-
tors Manual for proper procedures.
LOW PRESSURE GAUGE HOSE
The low pressure hose is BLUE with BLACK
STRIP. The low pressure port is located on the suc-
tion line.
HIGH PRESSURE GAUGE HOSE
The high pressure hose is RED with BLACK
STRIP. The high pressure port is located on the dis-
charge line.CONNECTION
(1) Remove the service port cap.
(2) Check all valves on the equipment being used
to verify they are closed.
(3) Attach the Quick-Disconnect coupler to the ser-
vice port and turn knob clockwise to depress sharder
valve.
DISCONNECT
(1) Turn coupler knob counter clockwise to release
sharder valve.
(2) Remove the coupler.
(3) Install the service port cap.
Fig. 1 Manifold Gauge Set
4 AIR CONDITIONINGJ