1988 JEEP CHEROKEE wiring
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![JEEP CHEROKEE 1988 Service Repair Manual \
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Is Air Flow Correct? Is The Fuse Blown?
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NO YES
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Check The Air Replace The Fuse
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\b Doors; Ensure
That There Are NO
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In The Vent
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YES Channels * Apply 12V Directly To
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\b Blower Motor
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* Does The Blower Motor Turn?
* Test Drive Belt Tension
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\b * Is The Clutch Defective?
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\b Replace Blower Motor
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\b * Apply 12V
Directly To YES
Clutch
\b * Is Clutch
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Defective? Is The Switch Defective?
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YES YES
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Replace Clutch Replace Switch
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Repair Wiring Repair The Wiring Harness
NO Harness \
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Low R-12 Refrigerant?
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YES Charge System
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Is The Pressure Switch Defective?
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NO
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Replace Pressure Switch Replace Expansion Valve
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CONDITION & POSSIBLE CAUSE
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![JEEP CHEROKEE 1988 Service Repair Manual \
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Compressor Runs Rough
* Incorrect oil or re](/manual-img/16/57037/w960_57037-113.png "JEEP CHEROKEE 1988 Service Repair Manual \
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Compressor Runs Rough
* Incorrect oil or re")
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Compressor Runs Rough
* Incorrect oil or refrigerant level.
* Internal compressor damage.
Compressor Intermittent or Inoperative
* Drive belt slipping.
* Faulty clutch air gap.
* Clutch coil wiring broken or frayed.
Noisy Compressor
* Mounting bolts loose.
* Clutch slipping.
* Improper charge in system.
* Bad clutch or pulley bearings.
* Incorrect oil level.
* Valve plate damaged.
* Piston slap.
Excessive Vibration
* Incorrect belt tension.
* Clutch loose.
* Pulley misaligned.
* System overcharged.
A/C Air Flow Stops on Acceleration
* Defective vacuum storage tank.
* Vacuum line separated or defective.
* Vacuum switch defective.
* Vacuum leak.
High Suction Pressure with Very Low Discharge Pressure
* Valve plate or gasket broken or deformed.
Very Low Suction and Discharge Pressure
* Low refrigerant charge.
* Compressor leak.
* System leak.
Heater Control Valve Does Not Close with Vacuum Applied
* Faulty heater control valve.
No Vacuum at Heater Control Valve with Lever at Extreme Left
* Vacuum source hose disconnected.
* Leaking vacuum hose.
* Faulty check valve.
* Control panel switch defective or misadjusted.
Frozen Evaporator Core
* Faulty thermostat.
* Thermostat capillary tube improperly installed.
* Thermostat not adjusted properly.
Condensation Dripping in Passenger Compartment
* Drain hose plugged or improperly installed.
* Insulation missing or improperly installed.
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TESTING
Note: The following test applies to all Jeep models except Cherokee
and Wagoneer.
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HEATER HOSES
HIGH PRESSURE RELIEF VALVES (HPRV)
IDLERS
IN-LINE FILTERS
METAL FITTINGS
METAL LINES
MIX AND AIR CONTROL DOORS (BLEND DOORS)
O-RINGS
ORIFICE TUBES
PILOT-OPERATED ABSOLUTES (POAS)
PLENUMS
PRESSURE CONTROL VALVES
PRESSURE SENSORS
PULLEYS
RADIATORS
RECEIVER-DRIERS
REFRIGERANT
REFRIGERANT OIL
RELAYS
SEALS
SERVICE PORTS
SPRING LOCK COUPLINGS
SUCTION THROTTLING VALVES (STVS)
SWITCHES (ELECTRICAL)
TENSIONERS
THERMISTORS AND PRESSURE SENSORS
THERMOSTATS AND HOUSINGS
VACUUM HOSES AND TUBES
VACUUM RESERVOIRS
VACUUM TUBES
VALVES IN RECEIVER (VIRS)
WATER PUMPS (ELECTRIC AUXILIARY)
WIRING HARNESSES AND CONNECTORS
MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
(1) a Pledge of Assurance to their Customers and (2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards
Page 132 of 1378
required.
Fitting type incorrect
(such as compression
fitting) ............... B ............ Require replacement.
Flange leaking .......... A .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Restricted internally ... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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CONNECTORS
See WIRING HARNESSES AND CONNECTORS .
CONTROL CABLES
CONTROL CABLE INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Binding ................. A .. Require repair or replacement.
Bracket bent, affecting
performance ............ A .. Require repair or replacement.
Bracket bent, not
affecting performance .. .. ........ No service suggested or
required.
Bracket broken, affecting
performance ............ A ............ Require replacement.
Bracket broken, not
affecting performance .. .. ........ No service suggested or
required.
Bracket corroded,
affecting performance .. A .. Require repair or replacement.
Bracket corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Bracket cracked, affecting
performance ............ A .. Require repair or replacement.
Bracket cracked, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket holes elongated,
affecting performance .. A .. Require repair or replacement.
Bracket holes elongated,
not affecting
performance ............ .. ........ No service suggested or
required.
Bracket loose, affecting
performance ............ A .. Require repair or replacement.
Bracket loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket missing ......... C ............ Require replacement.
Broken .................. A .. Require repair or replacement.
Cracked ................. 2 .. Suggest repair or replacement.
Page 155 of 1378
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted,
affecting performance .. A ........... (1) Require repair or
replacement.
Connector melted, not
affecting performance .. 2 ........... ( 1) Suggest repair or
replacement.
Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ ( 2) Require replacement.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Noisy ................... 2 ............ Suggest replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Vibration ............... 1 .. Suggest replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.
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WIRING HARNESSES AND CONNECTORS
WIRING HARNESS AND CONNECTOR INSPECTION \
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Condition Code Procedure
Application incorrect ... B .. Require repair or replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Circuit open ............ A .. Require repair or replacement.
Circuit resistance
(voltage drop) out of
Page 183 of 1378
be obtained. During high speeds "on" time may be 10 percent and "off"
time 90 percent. During low speeds with high electrical loads, "on"
time may be 90 percent and "off" time 10 percent.
SI SERIES
A rectifier bridge, connected to stator windings, contains 6
diodes (3 positive and 3 negative) molded into an assembly. This
rectifier bridge changes stator AC voltage into DC voltage, which
appears at output terminal.
Alternator field current is supplied through a diode trio
which is also connected to stator windings. A capacitor is mounted to
end frame, protecting rectifier bridge and diodes from high voltage
and suppressing radio interference noise.
TROUBLE SHOOTING
NOTE: See the TROUBLE SHOOTING - BASIC PROCEDURES article
in the GENERAL TROUBLE SHOOTING section.
TESTING
PRELIMINARY INFORMATION
NOTE: Before making electrical checks, visually inspect all
terminals for clean, tight connections. Check alternator
mounting bolts and drive belt tension. Battery must be in
good condition to test charging system.
TESTING (ON-VEHICLE)
CS SERIES
Over/Undercharged Battery (W/ STandard Instruments)
1) If an overcharging condition is suspected, run engine at a
moderate speed. Connect a voltmeter across battery terminals. If
voltmeter indicates more than 16 volts, replace alternator.
2) If an undercharging condition is suspected, disconnect
2
wire connector from alternator. Turn ignition on with engine off.
Connect a voltmeter between terminal "L" in wiring harness and ground.
Record reading.
3) If terminal "I" is used, connect voltmeter between
terminal "I" and ground. Record reading. If voltmeter reads battery
voltage, circuits are okay. If voltmeter reads zero, this indicates an
open circuit between terminal checked and battery. Repair as
necessary.
Overcharged Battery (W/ Gauges)
If an overcharging condition is suspected, run engine at a
moderate speed. Connect a voltmeter across battery terminals. If
voltmeter indicates more than 16 volts, replace alternator.
Alternator Output Test (W/ Standard Instruments Or Gauges)
1) Run engine at moderate speed, all electrical accessories
off. Measure voltage across battery, if above 16 volts, replace
alternator.
2) Connect an ammeter in circuit at "BAT" terminal of
alternator. Turn on all available accessories. Connect a battery load
tester across battery. Operate engine at 2000 RPM and adjust battery
load tester as required to obtain maximum current output while
Page 202 of 1378
Park ........................................... "B" & "C"
Reverse ........................................ "A" & "E"
Neutral ........................................ "B" & "C"
Drive ................................................ (1)
3 .............................................. "A" & "G"
1-2 ............................................ "A" & "H"
( 1) - No continuity should exist between any terminals.
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Fig. 4: Identifying Neutral Safety Switch Terminals
Courtesy of Chrysler Corp.
SPEED SENSOR
1) Disconnect electrical connector at speed sensor located on
adapter housing or extension housing. Connect ohmmeter leads between
speed sensor electrical terminals.
2) Rotate transmission output shaft and note ohmmeter
reading. Ohmmeter needle should fluctuate to indicate speed sensor
operation. Replace speed sensor if no reading is obtained.
THROTTLE POSITION SENSOR (TPS)
NOTE: Digital voltmeter must be used to check TPS.
1) Note location of TPS electrical connector. See Fig. 5.
Turn ignition on. Using digital voltmeter, check output voltage at
center terminal with throttle plate closed (idle position) and wide
open (full throttle).
2) With throttle plate closed (idle position), output voltag\
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should be greater than 200 millivolts. With throttle plate wide open
(full throttle), output voltage should be less than 4.8 volts.
3) Ensure output voltage gradually increases as throttle
plate is moved from closed to wide open throttle. If no voltage
exists, check for defective wiring circuits or connections. Replace
TPS if defective.
Page 267 of 1378
Fig. 117: Test 10A - Location of Transmission Connectors
Fig. 118: Test 10A - View of 7-Way Connector (Cherokee)
NOTE: See Fig. 115 for wiring diagram.