Isuzu N-Series. Manual - part 631

ENGINE ELECTRICAL 6D-17

Reassembly

To install, follow the removal steps in the reverse order,
noting the following points:

• Magnetic Switch
• Idle Gear
• Clutch  assembly
• Housing

1. Install the clutch asm to the magnetic switch.
2. Install the idle gear and housing.

Notice:
Do not fail to assemble the steel ball and the spring be-
tween the clutch and magnetic switch.
Assemble the roller to the idle gear in advance. 

Magnetic Switch
Temporarily connect the solenoid switch between the
clutch and the housing and run the following tests.
Complete each test within three to five seconds.

1. Pull-in test

Connect the battery negative terminal with the so-
lenoid switch body and the M terminal. When cur-
rent is applied to the 50 terminal from the battery
positive terminal, the pinion should flutter.

2. Hold-in test

Disconnect the lead at the M terminal. The pinion
should continue to flutter.

Legend

1. Roller
2. Idle gear
3. Steel ball

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N6A3515E

Legend

1. M terminal
2. 50 terminal

Legend

1. Disconnect

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6D-18 ENGINE ELECTRICAL

3. Return test

Connect the battery negative terminal to the 50 ter-
minal and the body. Connect the battery positive
terminal to the M terminal. The pinion will flutter.
When the lead to the 50 terminal is disconnected,
the pinion should immediately return to its station-
ary positions.

4. Current value

• Make connections as shown in the illustration,

and measure the current value.

Standard = 120 A or less

Notice:
For a battery, be sure to use one fully charged.
For lead wires, use thick ones since a large amount of
current flows through them.

Legend

1. 30 terminal

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N6A3519E

ENGINE ELECTRICAL 6D-19

CHARGING SYSTEM

General Description

The charging system is the IC integral regulator charging system and its main components are connected as shown
in Figure.
The regulator is a solid state type and it is mounted along with the brush holder assembly inside the generator in-
stalled on the rear end cover.
The generator does not require particular maintenance such as voltage adjustment. The rectifier connected to the
stators coil has nine diodes to transform A.C. voltage into D.C. voltage. This D.C. voltage is connected to the output
terminal of generator.
Generator (12V-50A)

Legend

1. Ball bearing

8. Slip ring

2. Pulley

9. Brush

3. Front cover

10. Rear cover

4. Fan

11. Vacuum pump

5. Stator

12. Through bolt

6. Rotor

13. Ball bearing

7. IC regulator

14. Oil seal

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6D-20 ENGINE ELECTRICAL

Diagnosis

General On-Vehicle Inspection
The operating condition of charging system is indicated by the charge warning lamp. The warning lamp comes on
when the starter switch is turned on “ON” position. The charging system operates normally if the lamp goes off when
the engine starts. If the warning lamp shows abnormality or if undercharged or overcharged battery condition is sus-
pected, perform diagnosis by checking the charging system as follows:
For 4JB1, 4JB1-TC

1. Check visually the belt and wiring connector.
2. With the engine in stop status, turn the starter

switch to “ON” position and observe the warning
lamp.

• If lamp does not come on:

Disconnect wiring connector from generator, and
ground the terminal “L” on connector side.

• If lamp comes on:

Repair or replace the generator.

N6A3522E