Mitsubishi Montero (2004+). Manual - part 389

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-11

12.Increase the engine speed to 2,500 r/min.
13.Read the value displayed on the voltmeter when 

the current output by the generator becomes 10 A 
or less.

14.If the voltage reading is within the value in the 

voltage regulation table, then the voltage regulator 
is operating normally.
If the voltage is outside the standard value, there 
is a malfunction of the voltage regulator or the 
generator (Refer to the following table).

15.After the test, lower the engine speed to the idle 

speed.

16.Turn the ignition switch to the "LOCK" (OFF) 

position.

17.Disconnect the negative battery cable.
18.Disconnect the ammeter, voltmeter and engine 

tachometer.

19.Connect the generator output wire to the 

generator "B" terminal.

20.Connect the negative battery cable.

VOLTAGE REGULATION TABLE

WAVE PATTERN CHECK USING AN 
OSCILLOSCOPE

M1161001200180

.

MEASUREMENT METHOD
Connect the oscilloscope special patterns pick-up to the gener-
ator "B" terminal.

.

STANDARD WAVEFORM

INSPECTION TERMINAL

VOLTAGE REGULATOR 
AMBIENT TEMPERATURE [

°C 

(

°F)]

STANDARD VALUE (V)

Terminal "S"

−20 (−4)

14.2 

− 15.4

20 (68)

13.9 

− 14.9

60 (140)

13.4 

− 14.5

80 (176)

13.1 

− 14.5

AKX00188

GENERATOR

OSCILLOSCOPE

"B" TERMINAL

PROBE

AB

Observation Conditions

FUNCTION

SPECIAL PATTERNS

Pattern height

Variable

Variable knob

Adjust while viewing the wave 
pattern

Pattern selector

Raster

Engine revolutions

Curb idle speed

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-12

NOTE: The voltage waveform of the generator "B" terminal can 
undulate as shown at left. This waveform is produced when the 
regulator operates according to fluctuations in the generator 
load (current), and is normal for the generator.
If the ripple height is abnormally high (approximately 2 V or 
more during idling), the wires between the generator "B" termi-
nal and the battery have broken due to fuse blowing, etc. The 
generator is usually operating properly.

.

ABNORMAL WAVEFORMS EXAMPLES
NOTE: The size of the waveform patterns can differ greatly, 
depending on the adjustment of the variable knob on the oscil-
loscope.
NOTE:  Identification of abnormal waveforms is easier when 
there is a large output current (regulator is not operating). 
(Waveforms can be observed when the headlights are illumi-
nated.)
NOTE: Check the conditions of the generator malfunction light 
(illuminated/not illuminated) also, and carry out a total check.

ABNORMAL WAVEFORMS

• Example 1

PROBABLE CAUSE: Open circuit in diode

AKX00189

0.4

(V)

0.2

  0

–0.2

–0.4

VOLTAGE AT
GENERATOR
"B" TERMINAL

TIME

AB

AKX00190

AKX00191

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-13

• Example 2

PROBABLE CAUSE: Short-circuit in diode

• Example 3

PROBABLE CAUSE: Open circuit in stator coil

• Example 4

PROBABLE CAUSE: Short-circuit in stator coil

AKX00192

AKX00193

AKX00194

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-14

GENERATOR ASSEMBLY

REMOVAL AND INSTALLATION

M1161001400645

Pre-removal Operation
• Under Cover Removal

• Air Cleaner Removal (Refer to GROUP 15, Air Cleaner 

P.15-6

.)

Post-installation Operation
• Drive Belt Tension Check (Refer to GROUP 00, Mainte-

nance Service 

P.00-41

.)

• Under Cover

• Air Cleaner Installation (Refer to GROUP 15, Air Cleaner 

P.15-6

.)

AC204070

1

2

44 ± 10 N·m
33 ± 7 ft-lb 

22 ± 4 N·m
16 ± 3 ft-lb 

AB

REMOVAL STEPS

1.

DRIVE BELT

2.

GENERATOR