1988 JEEP CHEROKEE ignition

assembly. Turn upside down. See Fig. 8. Set ohmmeter to low scale.
Connect leads to coil "BAT" and "TACH" terminals. If resistance
exceeds one ohm, replace ignition coil.
2) Set ohmmeter on high scale. Connect one lead to coil
secondary terminal and the other lead first to "TACH" terminal and
then to ground terminal. If resistance reading in BOTH instances is
infinity, replace ignition coil.
Fig. 8: Testing Ignition Coil Resistance, Integral coil system shown.
Courtesy of General Motors Corp.
PICK-UP COIL SHORT & RESISTANCE CHECKS

system. For testing, see appropriate IGNITION SYSTEM CHECK
flow chart in COMPUTERIZED ENGINE CONTROLS section. For
diagnosis of HEI system, refer to following diagnostic
chart. See Fig. 11.
Fig. 11: Ignition Sys Check (HEI Only), Testing applies to HEI
sys with mechanical weights and vacuum advance.
Courtesy of General Motors Corp.
OVERHAUL

REASSEMBLY
Ensure pick-up assembly arm is correctly installed on pin. If
not, arm can float and cause ignition timing to vary. To prevent
corrosion, ensure module terminals are lubricated with petroleum jelly
before installation. To prevent heat damage, coat bottom of module and
module rest pad in housing with silicone grease. Before installation
of roll pin in driven gear, ensure timing mark on roll pin and rotor
tip align. See Figs. 12 through 14.
Fig. 12: Exploded View of HEI Distributor
Courtesy of General Motors Corp.

BATTERY SPECIFICATIONS
CAUTION: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in the GENERAL INFORMATION
section.
All gasoline engine equipped models use group 58 batteries
with 390 or 475 amp cold crank rating. Models with 2.1L Turbo Diesel
engine use group 24 batteries with a 815 amp cold crank rating.
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
electrical system overload.
BATTERY WARNING
WARNING: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in GENERAL INFORMATION section.
BRAKE PAD WEAR INDICATOR
Indicator will cause a squealing or scraping noise, warning
that brake pads need replacement.
DIESEL FUEL ANTI-FUNGAL ADDITIVES
CAUTION: If fuel contamination due to fungi or other microorganisms is
suspected a fuel additive with a biocide may be used. Follow
the manufacturers dosage as recommended on product label. Use
biocides ONLY when necessary, excessive use can may cause
other fuel system problems.
DIESEL FUEL CONTAMINATION
WARNING: Diesel fuel system may be contaminated with fungi or other
microorganisms. Keep contaminated fuel away from open skin
cuts or sores to prevent skin irritation or infection.
DIESEL FUEL REQUIREMENTS
CAUTION: All diesel engines are to use Diesel Fuel #2 when the outside
temperature is above 20\bF (-7\bC). In temperatures that are
below 20\bF (-7\bC) use Diesel Fuel #1, this will reduce the
chance of the fuel thickening and forming wax.
Note: A Diesel Fuel #1 & #2 combination (Blended Fuel) may be\
used, and is recommended for mild winter driving.

ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
WARNING: Many solid state electrical components can be damaged by
static electricity (ESD). Some will display a warning label,
but many will not. Discharge personal static electricity by
touching a metal ground point on the vehicle prior to
servicing any ESD sensitive component.
ENGINE OIL
CAUTION: Never use non-detergent or straight mineral oil.
CAUTION: Do not use reclaimed fluid, mineral oil, fluid that was
stored in old or open containers, or fluid inferior to AMC
Standard AM 4101. Be sure to handle the fluid in clean
containers that will not introduce even a slight amount of
foreign liquids or particles. Such contamination of fluid
could lead to hydraulic system failure.
ENGINE OIL FILTER (GASOLINE)
CAUTION: Verify that proper Oil Filter is being used. Filters with
metric threads (M20 x 1.5) must be used with some engines.
Other engines use SAE type (3/4" x 16) threads, and must
use an oil filter with these threads. Possible engine damage
can occur with improper oil filter.
ENGINE OIL FILTER (TURBO DIESEL ONLY)
CAUTION: The engine oil filter has METRIC threads. Use of a filter
with improper threads can result in oil leakage and
possible engine damage. Look for thread size symbol M20x1.5
on filter.
FUEL SYSTEM SERVICE
WARNING: DO NOT bleed fuel lines on hot engine, as high exhaust
temperatures could cause fire. Use care when bleeding fuel
lines, as fuel is under extreme pressure and could penetrate
skin, causing personal injury. Wear safety goggles and
protective clothing when bleeding fuel lines.
WARNING: Relieve fuel system pressure prior to servicing any fuel
system component.
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if
overheated. DO NOT touch glass portion of bulb with bare hands. Eye
protection should be worn when handling or working around halogen
bulbs.
RADIATOR CAP
CAUTION: Always disconnect the fan motor when working near the
radiator fan. The fan is temperature controlled and could
start at any time even when the ignition key is in the OFF
position. DO NOT loosen or remove radiator cap when cooling
system is hot.
STARTING FLUID USE (TURBO DIESEL)

MAIN TE N AN CE R EM IN DER L IG HT R ESET P R O CED URES

1988 J e ep C hero ke e
1988-92 MAINTENANCE
Chrysler Motors Maintenance Reminder Lights
Jeep; Cherokee, Comanche, Wagoneer (1988-90), Wrangler
EMISSION MAINTENANCE INDICATOR LIGHT (1988-90)
Vehicles are equipped with an emission maintenance indicator
light on instrument cluster. This light will come on one time at 82,
500 miles to alert driver that emission service is required. At this
time, oxygen sensor and PCV valve must be replaced and all other
emission components should be inspected and serviced or replaced as
necessary.
Indicator timer is located under dash, near accelerator pedal
or to right of steering column. Timer cannot be reset. To turn off
light, timer must be replaced or disconnected. Since timer and sensor
are interdependent, if timer should fail prematurely, oxygen sensor
should be replaced at same time to preserve correct replacement
interval.
To replace timer on Cherokee, Comanche and Wagoneer models,
remove cruise control module (if equipped). Remove timer mounting
screws. Disconnect electrical connector. On Wrangler models, remove
timer mounting screws. Disconnect electrical connector. On all models,
install remaining components.
EMISSION MAINTENANCE INDICATOR LIGHT (1991-92)
Vehicles are equipped with an emission maintenance indicator
light on instrument cluster. This light will come on one time at 82,
500 miles to alert driver that emission service is required. At this
time, oxygen sensor must be replaced and all other emission components
should be inspected and serviced or replaced as necessary. Chrysler's
Diagnostic Readout Box (DRB-II) tester is required to reset the
emission maintenance indicator light.
Reset Procedure
Using DRB-II tester, access SELECT SYSTEMS. Select
appropriate engine. Select with or without A/C. Select FUEL &
IGNITION. Select ADJUSTMENTS. Select RESET EMR LIGHT. Reset EMR light.
When DRB-II is finished resetting light, DRB-II display will read EMR
LIGHT IS RESET.

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.

If test light glows, check tailgate window motor.
TAILGATE WINDOW MOTOR
Grand Wagoneer
1) Using a 12-volt test light, connect one end of test light
to ground and probe Tan wire at motor. Close safety switch and turn
tailgate window switch to "DOWN" position. If test light glows and
motor does not operate, replace motor. If test light does not glow,
check feed circuit to motor and repair as necessary.
2) Probe Brown wire at motor. Close safety switch and turn
tailgate window switch to "UP" position. If test light glows and motor
does not operate, replace motor. If test light does not glow, check
feed circuit to motor and repair as necessary.
SIDE WINDOW MASTER SWITCH CIRCUIT
1) Remove escutcheon and housing from master switch. Separate
terminal plate by releasing retainer hooks to expose terminal ends.
Turn ignition on.
2) Using a 12-volt test light, connect one lead to Black wire
and other lead to Red terminal. Repeat test at second Black wire. If
test light does not glow in either test, remove lead to Black terminal
and connect to chassis ground.
3) If test light glows, an open exists between master switch
and ground. If test light does not glow, it indicates a defective
circuit breaker or an opening in the Red wire from circuit breaker to
master switch.
SIDE WINDOW CONTROL SWITCH & MOTOR TEST
Grand Wagoneer
1) Connect test light between terminals of Orange and Yellow
wires. Operate control switch up and down. If test light glows in both
switch positions, wires, individual door and master switches are not
defective.
2) Disconnect White and Green motor leads at terminal plate,
and connect to Green and White leads. Operate master switch. If window
goes up and down, motor is okay, but switch is defective. If motor
does not operate, remove trim panel and check connections and leads to
motor. If motor operates, switch is defective.
SIDE WINDOW MOTOR
Connect test battery positive lead to one of the motor
terminals. Connect negative lead to other terminal. Motor should
rotate in one direction to go up or down. Reverse battery leads, motor
should rotate in opposite direction. If window does not move, replace
motor.
SWITCH VOLTAGE TEST
1) Turn ignition on. Remove switch from trim panel.
Disconnect terminal block on wiring harness from switch body. Connect
one lead of test light to Red wire terminal and other end to ground.
2) If test light glows, wiring between battery and switch is
functional. Check continuity in Black wire (ground). If test light
does not glow, check circuit breaker. If okay, check for a broken
wire.
SWITCH UP & SWITCH DOWN TEST