Mitsubishi Galant 9G. Manual — part 353

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-8

ON-VEHICLE SERVICE

GENERATOR OUTPUT LINE VOLTAGE DROP TEST

M1161000900669

Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

This test determines whether the wiring from the
generator "B" terminal to the positive battery terminal
(including the fusible link) is in good condition or not:

WARNING

Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.

1. Always be sure to check the following before the

test.

• Generator installation

• Generator drive belt tension (Refer to GROUP

00, General

− Maintenance Service − Drive Belts

(For Generator, Power Steering Pump and Air
Conditioning) (Check)

P.00-45

.)

• Fusible link

• Abnormal noise from the generator while the

engine is running.

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

position.

3. Disconnect the negative battery cable.
4. Connect a clamp-type DC test ammeter with a

range of 0

− 100 A to the generator "B" terminal

output wire.
NOTE: The way of disconnecting the generator
output wire and of connecting the ammeter is pos-
sibly not found the problem that the output current
is dropping due to the insufficient connection
between terminal "B" and the output wire.

5. Connect a digital-type voltmeter between the

generator "B" terminal and the positive battery
terminal. (Connect the positive lead of the
voltmeter to the "B" terminal, and then connect the
negative lead of the voltmeter to the positive
battery cable.)

6. Reconnect the negative battery cable.
7. Connect an engine tachometer or scan tool

MB991958.

8. Leave the hood open.
9. Start the engine.

AK203361AC

GENERATOR

AMMETER
(CLAMP-TYPE)

VOLTMETER
(DIGITAL-TYPE)

"B" TERMINAL

BATTERY

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-9

10.With the engine running at 2,500 r/min, turn the

headlights and other lights on and off to adjust the
generator load so that the value displayed on the
ammeter is slightly above 30 A.
Read the voltmeter. Voltage reading at or below
limit value means voltage drop between generator
and battery is OK.

Limit value: maximum 0.3 V

NOTE: When the generator output is high and the
value displayed on the ammeter does not
decrease to 30 A, set the value to 40 A. Read the
value displayed on the voltmeter at this time.
In this case the limit value becomes maximum 0.4
V.
Adjust the engine speed by gradually decreasing
it until the value displayed on the ammeter is 30
A. Take a reading of the value displayed on the
voltmeter at this time.

11.If the value displayed on the voltmeter is above

the limit value, there is probably a malfunction in
the generator output wire. Check the wiring
between the generator "B" terminal and the
positive battery terminal (including fusible link).
If a terminal is not sufficiently tight or if the
harness has become discolored due to
overheating, repair and then test again.

12.After the test, run the engine at idle.
13.Turn off all lights and turn the ignition switch to the

"LOCK" (OFF) position.
NOTE: Vehicles for Canada, the headlight, tail-
light, etc. remain lit even when the lighting switch
is in "OFF" position.

14.Disconnect the engine tachometer or scan tool

MB991958.

15.Disconnect the negative battery cable.
16.Disconnect the ammeter and voltmeter.
17.Connect the negative battery cable.
18.Run the engine for 10 minutes at an idle.

OUTPUT CURRENT TEST

M1161001000670

AK303633

GENERATOR

AMMETER
(CLAMP-TYPE)

VOLTMETER

IGNITION
SWITCH

LOAD

B

FR

L

S

G

GENERATOR
MALFUNCTION
LIGHT

COMBINATION METER

BATTERY

+

AB

–

PCM

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-10

Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

This test determines whether the generator outputs
normal current. For best results, use a charging sys-
tem tester. If not available, follow the steps below.

WARNING

Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.

1. Before the test, always be sure to check the

following.

• Generator installation

• Battery (Refer to GROUP 54A, Chassis Electrical

− Battery − On-vehicle Service − Battery Check

P.54A-5

.)

NOTE: The battery to be used should be slightly
discharged. The load in a fully-charged battery
will be insufficient and the test may not be able to
be carried out correctly.

• Generator drive belt tension (Refer to GROUP

00, General

− Maintenance Service − Drive Belts

(For Generator, Power Steering Pump and Air
Conditioning) (Check)

P.00-45

.)

• Fusible link

• Abnormal noise from the generator while the

engine is running.

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

position.

3. Disconnect the negative battery cable.

WARNING

Never use clips to connect the line. Loose
connections (for example, using clips) will
lead to a serious accident because of high
current.

4. Connect a clamp-type DC test ammeter with a

range of 0

− 120 A to the generator "B" terminal

output wire.

5. Connect a voltmeter with a range of 0

− 20 V

between the generator "B" terminal and ground.
(Connect the positive lead of the voltmeter to the
"B" terminal, and then connect the negative lead
of the voltmeter to ground.)

6. Connect the negative battery cable.
7. Connect an engine tachometer or scan tool

MB991958.

8. Leave the hood open.
9. Check to be sure that the reading on the voltmeter

is equal to the battery positive voltage.
NOTE: If the voltage is 0 V, the cause is probably
an open circuit in the wire or fusible link between
the generator "B" terminal and the battery positive
terminal or malfunctioning voltmeter.

10.After turning on the headlights, start the engine.

NOTE: Because the current from the battery will
soon drop after the engine is started, step 11
should be carried out as quickly as possible in
order to obtain the maximum current output value.

11.Immediately after setting the headlights to high

beam and turning the heater blower switch to the
highest position, increase the engine speed to
2,500 r/min and read the maximum current output
value displayed on the ammeter.

Limit value: 70 % of nominal current output

NOTE: For the nominal current output, refer to the
Generator Specifications.
NOTE: The current output value will depend on
the electrical load and the temperature of the gen-
erator body.
NOTE: If the electrical load is small while testing,
the specified level of current may not be output
even though the generator is normal. In such
cases, increase the electrical load by leaving the
headlights turned on for some time to discharge
the battery or by using the lighting system in
another vehicle, and then test again.
NOTE: The specified level of current also may not
be output if the temperature of the generator body
or the ambient temperature is too high. In such
cases, cool the generator and then test again.

12.The reading on the ammeter should be above the

limit value. If the reading is below the limit value
and the generator output wire is normal, remove
the generator from the engine and check the
generator.

13.Run the engine at idle speed after the test.
14.Turn the ignition switch to the "LOCK" (OFF)

position.

15.Disconnect the engine tachometer or scan tool

MB991958.

16.Disconnect the negative battery cable.
17.Disconnect the ammeter and voltmeter .
18.Connect the negative battery cable.
19.Run the engine for 10 minutes at an idle.

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-11

REGULATED VOLTAGE TEST

M1161001100666

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

• MB991519: Generator Harness Connector

This test determines whether the voltage regulator is
correctly controlling the generator output voltage.

WARNING

Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.

1. Always be sure to check the following before the

test:

• Generator installation

• Check to be sure that the battery installed in the

vehicle is fully charged. (Refer to GROUP 54A,
Chassis Electrical

− Battery − On-vehicle Service

− Battery Check

P.54A-5

.)

• Generator drive belt tension (Refer to GROUP

00, General

− Maintenance Service − Drive Belts

(For Generator, Power Steering Pump and Air
Conditioning) (Check)

P.00-45

.)

• Fusible link

• Abnormal noise from the generator while the

engine is running.

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

position.

3. Disconnect the negative battery cable.
4. Use the special tool (Generator harness

connector: MB991519) to connect a digital-type
voltmeter between the generator "S" terminal and
ground. (Connect the positive lead of the
voltmeter to the "S" terminal, and then connect the
negative lead of the voltmeter to a secure ground
or to the negative battery terminal.)

5. Connect a clamp-type DC test ammeter with a

range of 0

− 120 A to the generator "B" terminal

output wire.

6. Reconnect the negative battery cable.
7. Connect an engine tachometer, or scan tool

MB991958.

8. Turn the ignition switch to the "ON" position and

check that the reading on the voltmeter is equal to
the battery positive voltage.
NOTE: If the voltage is 0 V, the cause is probably
an open circuit in the wire or fusible link between
the generator "S" terminal and the battery positive
terminal or malfunctioning voltmeter.

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 10 A
or less.

AK303634

PCM

AB

BATTERY

IGNITION
SWITCH

AMMETER
(CLAMP-TYPE)

LOAD

BLACK

MB991519

VOLTMETER (DIGITAL-TYPE)

RED

YELLOW

BLUE

GENERATOR

B

FR

L

S

G

GENERATOR
MALFUNCTION
LIGHT

COMBINATION
METER