1988 JEEP CHEROKEE fog light

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DEFO GGER - R EA R W IN DO W

1988 J e ep C hero ke e
1988 Defoggers
REAR WINDOW
Jeep: All Models
DESCRIPTION & OPERATION
System consists of 2 vertical bus bars and horizontal rows of
heating elements fused to inside of glass, a control switch, an
indicator light, and timer relay.
The grid feed wire is connected to bus bar on driver's side
of window. Ground bus bar is on right side of vehicle. Timer/relay
receives current from fuse block. A circuit breaker protects defogger
circuit.
NOTE: On some Jeep models, defogger switch and electric tailgate
switch are serviced as an assembly.
TROUBLE SHOOTING
NOTE: Control switch testing is not available for Wrangler models.
1) On Cherokee, Comanche and Wagoneer models, turn ignition
switch to "ON" position. Check for current at "I" and "B" terminals.
See Fig. 1 . If there is no current, check circuit and repair as
necessary. Make sure that switch has a good ground through wire
connected to "G" terminal.
2) With a good ground circuit and ignition switch in "ON"
position, current should be present at "L" terminal. If there is no
current, replace control switch.
Fig. 1: Jeep Control Switch Terminals
3) On Grand Wagoneer models, turn ignition switch to "ON"
position and press defogger switch. Separate wiring harness at
connector under dash. Connect a 12-volt test light from Purple wire to

ground. Test light should light. Turn defogger switch to "OFF"
position. Test light should not light.
GRID
1) Using a voltmeter with a 0-15 volt range, contact bus bar
connecting grid lines on passenger's side of glass with negative lead
of voltmeter. Contact driver's side bus bar with positive lead.
2) Turn ignition and control switches to "ON" position.
Reading should be 10-14 volts. Lower voltage indicates a poor ground.
Attach negative voltmeter lead to ground. Voltage reading should not
vary.
3) Contact negative lead to passenger's side bus bar. Probe
each grid line at midpoint with positive lead. A 6-volt reading
indicates line is good. A zero volt reading indicates a break between
midpoint and driver's side bus bar line.
4) A 10-14 volt reading indicates a break between midpoint
and passenger's side bus bar line. Move positive lead toward break and
voltage will change when break is crossed.
NOTE: On some Jeep models feed wire and ground wires a reversed.
Fig. 2: Grid Continuity Voltage Drop
RELAY
NOTE: No relay testing is available for Wrangler models.

B+ Latch Relay On center of right front
wheelwell.
Choke Relay On right front wheelwell.
Door Lock/Unlock Relays Under dash, behind right kick
panel.
Fog Light Relay Behind right headlight, on
wheelwell.

Rear Window Defogger Relay Under instrument panel, to
right of steering column.
Rear Wiper Relay In tailgate, next to wiper
motor.
Starter Relay (Graphic 1) Behind right headlight, on
wheelwell.

\003* E LE C TR IC AL S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *

1 988 J e ep C hero ke e
GENERAL INFORMATION
Electrical System Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
ACTUATOR MOTORS (SOLENOIDS) (ELECTRIC)
ACTUATOR MOTORS (VACUUM)
AIR BAGS
ALTERNATORS AND GENERATORS
AMPLIFIERS
ANTENNAS
BATTERIES
BATTERY CABLES
BATTERY CABLES
BATTERY HOLD DOWN HARDWARE
BATTERY TRAYS AND HOLD DOWN HARDWARE
BATTERY WIRES
BELTS
BULB SOCKETS
BULBS, SEALED BEAMS AND LEDS
CD PLAYERS
CIGARETTE LIGHTER ASSEMBLIES
CIRCUIT BREAKERS
CLUTCH SWITCHES
CONNECTORS
CONTROL MODULES
CRUISE CONTROL BRAKE SWITCHES
CRUISE CONTROL CABLES
CRUISE CONTROL CLUTCH SWITCHES
CRUISE CONTROL LINKAGES AND CABLES
CRUISE CONTROL RESERVOIRS
CRUISE CONTROL TUBES
CRUISE CONTROL VACUUM DUMP RELEASE VALVES
CRUISE CONTROL VACUUM HOSES, TUBES AND RESERVOIRS
CRUISE CONTROL VEHICLE SPEED SENSORS
DEFOGGERS
DEFROSTERS
DELAYS
DIMMERS
ELECTRIC HEATERS
EQUALIZERS
FUSE BLOCKS
FUSE BOXES AND BLOCKS
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSIBLE LINKS
GAUGES
GENERATORS
GROUND CABLES AND STRAPS
GROUND STRAPS
HEADLIGHT ADJUSTERS
HEATING ELEMENTS (DEFROSTERS, DEFOGGERS, ELECTRIC HEATERS AND SEATS)
HORNS AND SIRENS

1 - 25 Amp
Rear Washer/Wiper.
2 - 15 Amp
Radio, Cigarette Lighter.
3 - 25 Amp
Blower Motor.
4 - 20 Amp
Turn Signal, Back-Up Lights, Rear Window Defogger Relay.
5 - 10 Amp
Dome Light, Courtesy Lights, Glove Box Light, Cargo Light,
Radio Memory, Power Mirrors, Teltak Connector.
6 - 15 Amp
Hazard Warning System, Stoplights.
7 - 10 Amp
Parking Lights, Headlight Warning Chime/Buzzer, Instrument
Panel Light Dimmer.
8 - 7.5 Amp
Gauges, Instrument Cluster, Seat Belt Warning, Headlight
Delay, Chime Module, Overhead Console.
9 - 5 Amp
Instrument Panel Illumination.
10 - 25 Amp
Rear Window Defogger.
11 - 30 Amp (Circuit Breaker)
Power Door Locks, Power Seats, Trailer Towing Wiring Harness.
12 - 10 Amp
ETR Radio, Power Antenna.
13 - Not Used (1984-87); 7.5 Amp (1988)
Transmission Control Unit.
14 - 25 Amp
Headlight Delay, Horns, Security Alarm.
15 - 5.5 Amp (Circuit Breaker)
Front Wiper.
16 - 30 Amp (Circuit Breaker)
Power Windows.
17 - 10 Amp
Clock, Security Alarm (Ign).
CAUTIONS & WARNINGS
REPLACING BLOWN FUSES
Before replacing a blown fuse, remove ignition key, turn off
all lights and accessories to avoid damaging the electrical system. Be
sure to use fuse with the correct indicated amperage rating. The use
of an incorrect amperage rating fuse may result in a dangerous

1 - 25 Amp
Rear Washer/Wiper
2 - 15 Amp
Radio, Cigarette Lighter
3 - 25 Amp
Blower Motor
4 - 20 Amp
Turn Signal, Back-Up Lights, Rear Window Defogger Relay
5 - 10 Amp
Dome Light, Courtesy Lights, Glove Box Light, Cargo Light,
Radio Memory, Power Mirrors, Teltak Connector
6 - 15 Amp
Hazard Warning System, Stoplights
7 - 10 Amp
Parking Lights, Headlight Warning Chime/Buzzer, Instrument
Panel Light Dimmer
8 - 7.5 Amp
Gauges, Instrument Cluster, Seat Belt Warning,
Headlight Delay, Chime Module, Overhead Console
9 - 5 Amp
Instrument Panel Illumination
10 - 25 Amp
Rear Window Defogger
11 - 30 Amp (Circuit Breaker)
Power Door Locks, Power Seats, Trailer Towing Wiring Harness
12 - 10 Amp
ETR Radio, Power Antenna
13 - Not Used (1984-87)
7.5 Amp (1988)
Transmission Control Unit
14 - 25 Amp
Headlight Delay, Horns, Security Alarm
15 - 5.5 Amp (Circuit Breaker)
Front Wiper
16 - 30 Amp (Circuit Breaker)
Power Windows
17 - 10 Amp
Clock, Security Alarm (IGN)

PO W ER W IN DO W S

1988 J e ep C hero ke e
1988 Power Windows
JEEP SIDE & TAILGATE WINDOWS
Cherokee, Comanche, Grand
Wagoneer, Wagoneer
DESCRIPTION
All models have a tape-driven window regulator system in the
side doors, and a mechanical regulator in rear door of Grand Wagoneer.
On Grand Wagoneer, the tailgate window operates on 2 circuits, from an
instrument panel switch or an external key switch at the tailgate.
Side windows are operated by individual switches at each door, or by a
complete set of control switches at the instrument panel or drivers
door. The system is protected by a 30 amp circuit breaker in the fuse
panel.
TESTING
NOTE: Ensure instrument panel tailgate switch is properly grounded
as motor grounds through switch. The electric tailgate and
defogger switch are serviced as an assembly.
INSTRUMENT PANEL TAILGATE SWITCH
Grand Wagoneer
1) Turn ignition on. Using a 12-volt test light, connect one
end of test light to ground and probe Red wire. If test light does not
glow, repair feed circuit.
2) If test light glows, probe Brown wire with switch in "UP"
position. If test light does not glow, replace switch. If test light
glows, move switch to "DOWN" position and probe Tan wire. If test
light does not glow, replace switch. If test light glows, check
tailgate window switch.
TAILGATE WINDOW SWITCH
Grand Wagoneer
1) Using a 12-volt test light, connect one end of test light
to ground and probe Red wire of tailgate window switch. If test light
does not glow, repair feed circuit.
2) If test light glows, probe Tan wire. Turn tailgate switch
to "DOWN" position. If test light does not glow, replace switch. If
test light glows, probe Brown wire. Turn tailgate switch to "UP"
position.
3) If test light does not glow, replace switch. If test light
glows, check tailgate window safety switch.
TAILGATE WINDOW SAFETY SWITCH
Grand Wagoneer
1) Using a 12-volt test light, connect one end of test light
to ground and probe Brown wire of safety switch. Turn tailgate switch
to "UP" position. If test light glows, voltage is present at switch.
If test light does not glow, check feed circuit and repair as
necessary.
2) Probe Brown wire. Turn tailgate switch to "UP" position
and close safety switch. If test light does not glow, replace switch.