Mitsubishi Lancer Evolution X. Manual - part 95

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-11

9. Check to be sure that all lights and accessories 

are off.

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

the current output by the generator becomes 15 A 
or less.

13.If the voltage reading conforms to 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).

NOTE: When the voltage is approximately 12.8 V, 
the G-terminal is supposed to have a short circuit 
to the earth. Check the circuits relating to the 
G-terminal on the generator. (Refer to GROUP 
13A 

−

 Troubleshooting 

−

 Inspection chart for trou-

ble symptoms)

14.After the test, lower the engine speed to idle.
15.Turn the ignition switch to the "LOCK" (OFF) 

position.

16.Disconnect the engine tachometer or scan tool 

MB991958.

17.Disconnect the negative battery cable.
18.Disconnect the ammeter and voltmeter.
19.Remove the special tool (Generator harness 

connector: MB991519), and return the connector 
to the original condition.

20.Connect the negative battery cable.

VOLTAGE REGULATION TABLE

WAVE PATTERN CHECK USING AN 
OSCILLOSCOPE

M1161001200663

.

MEASUREMENT METHOD

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

.

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 − 14.6

80 (176)

13.1 − 14.5

AK604150

Generator

CH1

AB

"B" terminal

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-12

STANDARD WAVEFORM

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.

.

Observation Conditions

FUNCTION

SPECIAL PATTERNS

Pattern height

Variable

Variable knob

Adjust while viewing the 
wave pattern

Pattern selector

Raster

Engine revolutions

Curb idle speed

AK604151

0.4

(V)

0.2

0

–0.2

–0.4

Voltage at
generator
"B" terminal

Time

AB

AKX00190

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-13

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 or short circuit in diode

• Example 2

PROBABLE CAUSE: Open circuit in stator coil (In stator 
coil)

• Example 3

PROBABLE CAUSE: Open circuit in stator coil (Open cir-
cuit between stator coil and diode)

AK703778

AK703780

AK703781

CHARGING SYSTEM

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ENGINE ELECTRICAL

16-14

• Example 4

PROBABLE CAUSE: Short circuit in stator coil

GENERATOR ASSEMBLY

REMOVAL AND INSTALLATION

M1161001403387

AK703782

Pre-removal operation
• Fan, Fan Motor and Fan Shroud Assembly Removal 

(Refer to GROUP 14, Radiator 

P.14-32

).

• Drive Belt Removal (Refer to GROUP 11A, Crankshaft 

Pulley 

P.11A-21

).

Post-installation operation
• Drive Belt Installation (Refer to GROUP 11A, Crankshaft 

Pulley 

P.11A-21

).

• Drive Belt Tension Check (Refer to GROUP 11A, On-vehi-

cle Service − Drive Belt Tension Check 

P.11A-7

).

• Fan, Fan Motor and Fan Shroud Assembly Installation 

(Refer to GROUP 14, Radiator 

P.14-32

).

AC807419

2

3

6

5

4

AC

12 ± 2 N·m
102 ± 22 in-lb

44 ± 10 N·m
32 ± 7 ft-lb

44 ± 10 N·m
32 ± 7 ft-lb

23 ± 6 N·m
17 ± 4 ft-lb

48 ± 7 N·m
35 ± 5 ft-lb

1

Removal steps 

1.

Idler pulley

2.

A/C compressor and clutch 
assembly connector connection

<<

A

>>

>>

A

<<

3.

A/C compressor and clutch 
assembly

4.

Generator connector connection

5.

Generator terminal connection

<<

B

>>

6.

Generator assembly

Removal steps (Continued)