ignition system MITSUBISHI MONTERO 1987 1.G Workshop Manual

Service Manual
MONTERO
1987 : Volume 2
FOREWORD
This Service Manual has been prepared with the
latest service information available at the time of
publication. It is subdivided into various group
categories and each section contains diagnosis,
disassembly, repair, and installation procedures
along with complete specifications and tightening
references. Use of this manual will aid in properly
performing any servicing necessary to maintain or
restore the high levels of performance and reliability
designed into these outstanding vehicles.
WE SUPPORT
VOLUNTARY TECHNICIAN
CERTIFICATION THROUGH
MITSUBISHI MOTOR SALES OF AMERICA. Inc.
Mitsubishi Motors corporation reserves the right to make changes in
design or to make additions to or improvements in its products without
imposing any obligations upon itself to install them on its products
previously manufactured.
I
GROUP/SECTION INDEX ‘kme-.
INTRODUCTION ..............................
Electrical ...........................................
Electrical System Parts
Location .........................................
Relays, Control Units, Sensors,
Fuses, Groundings
Inspection of Harness
Connector ......................................
Wiring Harness .............................
Charging System ..........................
Starting System ............................
Ignition System .............................
Meters and Gauges ......................
Lighting System .............................
Wiper and Washer System ..........
Horn ...............................................
Accessory ......................................
Audio System ................................
Back Door Window Defogger ......
Automatic Free-wheeling Hub
Indicator System ..........................
Heaters and Air-conditioning .........
Heaters ..........................................
Air-conditioning ............................
**, For Engine Chassis & Body refer to
0 1986 Mitsubishi Motors Corporation Printed in Japan

INTRODUCTION - Precautions Before Service 9
nm (in.)
so0059
PARTS
When replacing parts, use MITSUBISHI genuine parts.
VEHICLE WVASHING
If high-pressure car-washing equipment or steam car-washing
equipment is used to wash the vehicle, be sure to maintain the
spray nozzle at a distance of at least 300 mm (1 1.8 in.) from
any plastic parts and all opening parts (doors, luggage
compartment, etc.).
SERVICING THE ELECTRICAL SYSTEM
When servicing the electrical system, disconnect the negative
cable terminal from the battery.
Caution
Before connecting or disconnecting the negative cable, be
sure to turn off the ignition switch and the lighting switch.
(If this is not done, there is the possibility of semiconductor
parts being damaged.)
WIRING HARNESSES
1. Secure the wiring harnesses by using clamps so that there
is no slack. However, for any harness which passes to the
engine or other vibrating parts of the vehicle, allow some
slack within a range that does not allow the engine
vibrations to cause the harness to come into contact with
any of the surrounding parts. Then secure the harness by
using a clamp.
In addition, if a mounting indication mark (yellow tape) is
on a harness, secure the indication mark in the specified
location.
2. If any section of a wiring harness contacts the edge of a
part, or a corner, wrap the section of the harness with tape
or something similar in order to protect it from damage.
F161711
* :, :, 1 STB Revision

8-1
ELECTRICAL
CONTENTS
NOBAA-
ACCESSORY ......................................................
188
Cigarette Lighter ............................................
,190
Clock ...............................................................
,191
AUDIO SYSTEM ................................................
.192
AUTOMATIC FREE-WHEELING HUB
INDICATOR SYSTEM ........................................
208
Automatic Free-wheeling Hub
Indicator Control Unit
..................................... ,216
Pulse Generator ..............................................
215
BACK DOOR WINDOW DEFOGGER
................ .203
Defogger switch ............................................
,206
Printed Heater Lines
...................................... ,207
CHARGING SYSTEM .........................................
71
Alternator ........................................................
83
Service Adjustment Procedures
..................... 77
Battery Charging ........................................
82
Inspection of Battery ..................................
81
Output Current Test ...................................
78
Regulated Voltage Test ..............................
79
Voltage Drop Test of Alternator Output
Wire ............................................................
77
ELECTRICAL SYSTEM PARTS LOCATION
...... 2
Diode ...............................................................
5
Fusible Link and Fuse
..................................... 6
Grounding .......................................................
7
Relay and Control Unit ....................................
2
Sensor .............................................................
4
HORN ..................................................................
184
Horn Switch
.................................................... 187
IGNITION SYSTEM ............................................
105
Ignition Switch
................................................ 122
Ignition System ...............................................
1 14
Service Adjustment Procedures
.................... .l 1 1
Checking Ignition System
..........................
11 1
Checking Ignition Timing
...........................
11 1
Spark Plug Cable Test
................................
1 12
Spark Plug Test
.......................................... 1 12 INSPECTION OF HARNESS CONNECTOR ...... 9
Check for Improper Engagement of
Terminal .......................................................... 9
Continuity and Voltage Test for Connector .... 9
Engaging and Disengaging of Connector
Terminal ..........................................................
9
LIGHTING SYSTEM ........................................... 143
Column Switch
................................ .
.............. .I59
Dimmer Control Switch
................................. .I62
Hazard Warning Switch
................................. .I61
Headlight ........................................................ ,158
Service Adjustment Procedures
.................... .I57
Headlight Aiming .......................................
157
METERS AND GAUGES .................................... 123
Service Adjustment Procedures
.................... .I30
Fuel Gauge Simple Test ................................. .I31
Fuel Gauge Unit Inspection ........................... .I31
Oil Pressure Gauge Simple Test
.................... .I32
Oil Pressure Gauge Unit Simple Test
............ ,132
Speedometer Inspection
............................... .I30
Tachometer Inspection .................................. ,130
Voltage Meter Simple Test
............................ .I33
Water Temperature Gauge Simple Test
....... ..I3 1
Water Temperature Gauge Unit Inspection
. ..I3 2
STARTING SYSTEM .......................................... 91
Starter Motor ............ ....................................... 97
WIPER AND WASHER SYSTEM
....................... .163
WIRING HARNESS ............................................ 13
Centralized Junction ....................................... 69
Circuit Diagram ............................................... 34
Configuration Diagram .................................... 27
How to Read Wiring Diagrams ....................... 20
Troubleshooting .............................................. 13

WIRING HARNESS - HOW BO Read Wiring Diagrams 8-23
(4) Indication of fuses, fusible links and centralized relays
The fuses and fusible links in a circuit diagram are indicated by a wave symbol (-) and a double wave symbol
(~1, respectively. At a centralized junction, the fuses are given fuse numbers and centralized relays are given
connector symbols.
Example of centralized junction symbol: A - 01 x
Centralized junction indication symbol
Connector’s unique number (serial number)
Connector symbol
(5) Indication of ground point
The ground point in a circuit diagram is marked by a ground symbol, making it possible for you to refer to a
wiring harness configuration diagram and to ELECTRICAL SYSTEM PARTS LOCATION (Grounding).
(6) Indication of wires
In a circuit diagram, the wire diameter and wire color are shown for each wire. If there are several wires
of the same color in a connector, their wire color indication symbols should be such symbols as “I and
“2 for identification.
On connectors like this one given a central-
to CENTRALIZED JUNCTION for connector
1 shaoe. etc.
-I Headlight relay ignition switch
Dome light
I II I B-35 B-68b
P:8-47)
IEU
I ’ 2 I
RL
2-RL
0 III- BI B -----____________
L - - - - - _ _ _ _ _ __ _ _ _ _ _
B-39
Refer to Item (5).
Refer to Item (6)
The connector B-39 has two wires identical
in color (RL), so they are given identification
symbols *I and *2 in order to distinguish
them. 1 ST6 Revision

8-42 WIRING HARNESS - Overdrive Control System Circuit
5 OVERDRIVE CONTROL SYSTEM CIRCUIT
/ Sub fusible link
$in fusible
a
I 1
To combination meter
[Refer to P.8-52.1 ~ 0.85-W
i
To alternator
[Refer to P.8-37.1
~ 0.85-W
To column switch
[Refer to P.8-51.1 ~ 0.85-RL
Ignition switch
Multi-purpose
fuse
Remarks Combination meter
(I) For information concerning the ground points (example:
RLI 1
0). refer to P.8-7. IyRw 1 1 I
4
(2) The symbols 0, 0, etc. indicate that the wiring is
connected (using the same numerical symbol) to the
facing page.
(In other words, 0 on the right page is connected to 0 on
the left page.)
1 STB Revision -7

CHARGING SYSTEM -Troubleshooting 8-75
TROUBLESHOOTING
NOBEH-
Symptom Probable cause
Remedy Reference
we
Charging warning in- Fuse blown
dicator does not light
with ignition switch Light burned out
“ON” and engine off. 1
1 Wiring connection loose Check fuses
Replace light
Tighten loose connections 8-70
-
-
Charging warning in-
dicator does not go
out with engine
running
(Battery requires fre-
quent recharging)
L
t
Run-down battery
c
Electronic voltage regulator faulty
Drive belt loose or worn
Battery cables loose, corroded or worn
Fuse blown
Fusible link blown
Electronic voltage regulator or alternator
faulty
Wiring faulty
Drive belt loose or worn
Wiring connection loose or open circuit
Fusible link blown Replace voltage regulator
Adjust tension or replace drive
belt
Repair or replace cables
Check fuses
Replace fusible link
Test alternator
Repair wiring
Adjust tension or replace drive
belt
Tighten loose connection or
repair wiring
Replace fusible link 8-79
Refer to
GROUPS.
8-8 1
8-70
8-69
8-77
8-79
-
Refer to
GROUP 9.
-
8-69
Poor grounding 1 Repair
I-
I I I Electronic voltage regulator or alternator
faulty Test alternator 8-77
8-79
Overcharge Decrease in life of battery
Replace battery
8-81 I
Electronic voltage regulator faulty Replace voltage regulator 8-79
STB Revision

8-76 CHARGING SYSTEM - Circuit Diagram
3 CHARGING CIRCUIT
Battery Ignition switch
OFF
Main
m fusible ’ L
link
A-02
fl.3-Br 1~5~~
, A-23 Sub fusible link
(IGN . SW)
IAM IG ] c-55
3
3
A m
A
To turn signal flasher
unit [Refer to P.8-49.1 Multi-
n, Irnn4P
ComSeter
Remark
For information concerning the ground points (example:
q ),
refer to P.8-7. 37W605
Wiring color code
B: Black Br: Brown G: Green Gr: Gray L: Blue Lg: Light green
LI: Light blue 0: Orange P: Pink R: Red Y: Yellow W: White
1 STB Revision

CHARGING SYSTEM - Service Adjustment Procedures 8-77
SERVICE ADJUSTMENT PROCEDUREswmAB
lEL15I
INSPECTION OF THE CHARGING SYSTEM
VOLTAGE DROP TEST OF ALTERNATOR OUTPUT WIRE
This test judges whether or not the wiring (including the fusible
link) between the alternator B terminal and the battery (+) terminal
is sound by the voltage drop method.
Preparation
(1) Turn the ignition switch to “OFF”.
(2) Disconnect the battery ground cable.
(3) Disconnect the alternator output lead from the alternator “B”
terminal.
(4) Connect a DC ammeter (0 to 100 A) in series to the “B”
terminal and the disconnected output lead. Connect the (+)
lead of the ammeter to the “B” terminal and the (-) lead to
the disconnected output wire.
NOTE
Use of a clamp type ammeter that can measure current with-
out disconnecting the harness is preferred. The reason is that
when checking a vehicles that has a low output current due to
poor connection of the alternator “B” terminal, such poor con-
nection is corrected as the “B” terminal is loosened and a test
ammeter is connected in its place and as a result, causes for
the trouble may not be determined.
(5) Connect a digital voltmeter between the alternator “B” termi-
nal and battery (+) terminal. Connect the (+) lead wire of the
voltmeter to the “B” terminal and the (-) lead wire to the
battery (+) terminal.
(6) Connect the battery ground cable.
(7) Leave the hood open.
Test
(1) Start the engine.
(2) Turn on or off the headlights and small lights and adjust the
engine speed so that the ammeter reads 20 A and read off the
voltmeter indication under this condition.
Result
(1) It is okay if the voltmeter indicates the standard value. ’
Standard value : 0.2 V max.
(2) If the voltmeter indicates a value that is larger than the stan-
dard value, poor wiring is suspected, in which case check the
wiring from the alternator “B” terminal to fusible link to bat-
tery (+) terminal. Check for loose connection, color change
due to overheated harness, etc. and correct them before test-
ing again.
(3) Upon completion of the test, set the engine speed at idle. Turn
off the lights and turn off the ignition switch.
(4) Disconnect the battery ground cable.
(5) Disconnect the ammeter and voltmeter that have been con-
nected for the test purpose.
(6) Connect the alternator output wire to the alternator “B” ter-
minal.
(7) Connect the battery ground cable.
( STB Revision

8-78 CHARGING SYSTEM - Service Adiustment Procedures
80A
n
Relay with diode
Voltmeter
Ammeter Iad
176
OUTPUT CURRENT TEST
This test judges whether or not the alternator gives an output
current that is equivalent to the nominal output.
Preparation
(1) Prior to the test, check the following items and correct as
necessary.
(a) Check the battery installed in the vehicle to ensure that it
is in sound state*. The battery checking method is de-
scribed in “BATTERY”.
NOTE
*The battery that is used to test the output current should
be one that has been rather discharged. With a fully
charged battery, the test may not be conducted correctly
due to an insufficient load.
(b) Check tension of the alternator drive belt. The belt tension
check method is described in “GROUP 7 COOLING -
Service Adjustment Procedures”.
(2) Turn off the ignition switch.
(3) Disconnect the battery ground cable.
(4) Disconnect the alternator output wire from the alternator “B”
terminal.
(5) Connect a DC ammeter (0 to 100 A) in series between the “B”
terminal and the disconnected output wire. Connect the (+)
lead of the ammeter to the “B” terminal and connect the (-)
lead wire to the disconnected output wire.
NOTE
Tighten each connection by bolt and nut securely as a heavy
current will flow. Do not relay on clips.
(6) Connect a voltmeter (0 to 20 V) between the “B” terminal and
ground. Connect the (+) lead wire to the alternator “B” ter-
minal and (-) lead wire to a sound ground.
(7) Set the engine tachometer and connect the battery ground
cable.
(8) Leave the engine hood open.
Test
(1) Check to see that the voltmeter reads the same value as the
battery voltage.
If the voltmeter reads 0 V, an open circuit in the wire between
the alternator “B” terminal and battery (-) terminal, a blown
fusible link or poor grounding is suspected.
(2) Turn on the headlight switch and start the engine.
(3) Set the headlight at high beam and the heater blower switch
at HIGH, quickly increase the engine speed to 2500 rpm and
read the maximum output current value indicated by the am-
meter.
NOTE
After the engine start up, the charging current quickly drops.
therefore, above operation must be done quickly to read max-
imum current value correctly.
[ STB Revision
--I

CHARGING SYSTEM - Service Adjustment Procedures 8-79
Result
(1) The ammeter reading must be higher than the limit value. If it
is lower but the alternator output wire is normal, remove the
alternator from the vehicle and check it.
Limit value : 31 A min.
Caution
1. The nominal output current value is shown on the
nameplate affixed to the alternator body.
2. The output current value changes with the electrical
load and the temperature of the alternator itself.
Therefore, the nominal output current may not be ob-
tained if the vehicle electrical load at the time of test is
small. In such a case, keep the headlights on to cause
discharge of the battery or use lights of another vehi-
cle as a load to increase the electrical load. The nom-
inal output current may not be obtained if the temper-
ature of the alternator itself or abmient temperature is
too high. In such a case, reduce the temperature be-
fore testing again.
(2) Upon completion of the output current test, lower the engine
speed to the idle speed and turn off the ignition switch.
(3) Disconnect the battery ground cable.
(4) Remove the test ammeter and voltmeter and the engine ta-
chometer.
(5) connect the alternator output wire to the alternator “B” ter-
minal.
(6) Connect the battery ground cable.
REGULATED VOLTAGE TEST
The purpose of this test is to check that the electronic voltage
regulator controls the voltage correctly.
Preparation
(1) Prior to the test, check the following items and correct if nec-
essary.
(a) Check the battery installed on the vehicle to see that it is
fully charged. For battery checking method, see “BAT-
TERY”.
(b) Check the alternator drive belt tension. For belt tension
check, see “GROUP 7 COOLING - Service Adjustment
Procedures”.
(2) Turn the ignition switch to “OFF”.
(3) Disconnect the battery ground cable.
(4) Connect a digital voltmeter between the “S” terminal of the
alternator and ground. Connect the (+) lead of the voltmeter to
the “S” terminal of the alternator, inserting from the wire side
of the 2-way connector and connect the (-1 lead to sound
ground or battery (-) terminal.
1 ST6 Revision