engine ISUZU KB P190 2007 Workshop Repair Manual

6D-6 ENGINE ELECTRICAL (4JK1/4JJ1)
No charging
Possible problem Countermeasure
Dead battery Replace
Open or shorted wiring
Open or shorted ammeter
Loose wiring connections Repair
One or more generator coils open or shorted
Bad diode
Bad regulator Replace
Loose regulator connections
Repair

Inadequate charging
Possible problem Countermeasure
Dead battery Replace
Open or shorted wiring
Loose wiring connections Repair
Loose generator drive belt
Adjust belt tension
Stator coil intermittent short
Bad diode Replace
Loose battery connections
Repair
Bad regulator Replace
Loose regulator connections Repair

Excessive charging
Possible problem Countermeasure
Bad regulator Replace

Unstable charging current
Possible problem Countermeasure
Open wiring connection or broken wire Repair
Loose generator drive belt Adjust belt tension
Open or shorted stator coil Replace
Loose terminal connections Repair
Bad regulator Replace
Loose regulator terminal connections Repair

Abnormal operating noise
Possible problem Countermeasure
Loose generator drive belt Adjust belt tension
Bad bearing Replace
Loose rotor core or stator core Repair
Bad diode Replace
Open or shorted stator coil Replace


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ISUZU KB P190 2007

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-7
Diagnosis
On-vehicle Inspection
The charging system warning light tells the vehicle
operator of possible problems with the system.

W hen the ignition switch is moved to the ON position,
the light turns on. The light turns off immediately afte
r
the engine is started. If the light turns on during engine
operation, there is a problem with the charging system.
Perform the checks described below.
1. Check the belt (broken or loose).
2. Check the harness connectors (loose o
r
disconnected).
3. W ith the engine off, turn the ignition switch to the ON position. If the warning lamp does not light,
remove the harness connector from the generator.
Ground the connector IG terminal. The lamp
should light. If it does not, the bulb is burned out.
Replace the bulb.
4. Start the engine. If the warning lamp remains on, the generator must be repaired or replaced.





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6D-8 ENGINE ELECTRICAL (4JK1/4JJ1)
Specifications
Battery power Volts 12
Generator output Amperes 90
Rotational direction (Viewed from pulley)  Clockwise
Rated speed 5,000
Maximum speed rpm
18,000


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ENGINE ELECTRICAL (4JK1/4JJ1) 6D-9
Unit Servicing (4JJ1)



RTW 56DLF000101
Legend
1. Pulley Nut
2. Pulley
3. Front Cover Assembly
4. Rotor Assembly
5. Stator
6. Through Bolts
7. Nuts
8. Terminal Insulation Plate
9. Rear Cover Assembly
10. Rectifier
11. Brush Holder
12. Regulator Assembly



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ISUZU KB P190 2007

6D-10 ENGINE ELECTRICAL (4JK1/4JJ1)
Disassembly
1. Remove the through bolts.
2. Insert a flat-blade screwdriver between the front cover and the stator. Pry the parts apart.
3. Separate the front cover/rotor assembly from the rear cover/stator assembly.




RTW 56DSH000301
4. Place the front cover and rotor in a vise.
5. Remove the pulley nut and the pulley.
6. Remove the rotor from the front cover.




RTW 56DSH000501
7. Remove the screw from the front cover.

8. Remove the bearing retainer and the bearing.




RTW 56DSH000601
9. Remove the B-terminal nut.
10. Remove the rectifier and the brush holder.
11.Remove the rear cover from the stator.



RTW 56DSH000401
12.Remove the bolts securing the stator terminal to
the rectifier.


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ISUZU KB P190 2007

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-11
13.Remove the stator.







066RS030
14.Remove the bolts securing the regulator, the
rectifier, and the brush holder. Separate the parts.







066RW 025
Inspection and Repair
Repair or replace any parts found to be excessively
worn or damaged during the inspection procedure.
Rotor Assembly
1. Check for dirty or rough slip ring surfaces. Remove
dirt from the surfaces with a clean rag. Use No.
500 or No. 600 sandpaper to smooth the surfaces.
2. Measure the slip ring diameters. Replace the slip ring if the diameter is less than the specified limit.

Slip ring diameter mm (in)
Standard 27 (1.063)
Limit 26 (1.024)





066RS032
3. Measure the electrical resistance between the slip
rings. If the resistance is greater than the specified
limit (open circuit), repair is required.

Slip ring resistance Ω
Less than 3.75






066RS033


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6D-12 ENGINE ELECTRICAL (4JK1/4JJ1)
4. Check for conductivity between the slip rings and
the rotor core. If there is continuity, the roto
r
assembly must be replaced.






066RS017
Stator Coil
1. Measure the stator coil resistance. If the
resistance is less than the specified value, the
stator coil must be replaced.
Stator coil resistance
0.07Ω at 20 °C (68 °F)






066RS034
2. Measure the resistance between the stator coil
and the stator core. If the resistance is less than
the specified value, the stator coil must be
replaced.


Stator coil/core resistance MΩ
1







066RS035
Brushes
Measure the brush height. If the height is less than the
specified limit, the brushes must be replaced.
Brush height mm (in)
Standard 18 (0.709)
Limit 5.5 (0.217)








066RW 024

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ISUZU KB P190 2007

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-13
Rectifier
Measure each of the diode resistances in both
directions (anode/cathode and cathode/anode). If any o
f
the diodes have the same resistance in both directions,
the rectifier must be replaced.



066RS036

Regulator Assembly
There are 3 checkpoints (12V batteries, 10 ohms 3W
resistor, 0-50V/0.5V steps, and 300 ohms 12W variable
resistor). Refer to the schematic below.

Measuring Procedure
1. Measure the voltage (BAT) at the V1 checkpoint. A
10-13 volt reading indicates that the BAT battery is
good.
2. Measure the voltage at checkpoints V1 and V2 as
you gradually increase the resistance of the
variable resistor from 0. The voltage at V1 should
change with the voltage at V2. If it does not, the
regulator is damaged and must be replaced.
3. Measure the voltage at checkpoint V3 with the variable resistor setting fixed. If the measured
voltage is 14.4 ± 0.3, the regulator is good. If the
measured voltage is outside this range, the
regulator is damaged and must be replaced.





RTW 56DMF000301

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ISUZU KB P190 2007

6D-14 ENGINE ELECTRICAL (4JK1/4JJ1)
Reassembly
Follow the disassembly steps in reverse order to
reassemble the generator. Pay close attention to the
items below.
• Be very careful not to reverse battery polarity.
Reversed battery polarity will destroy the rectifie
r
diodes.
• Do not ground the generator B-terminal. Heat and
fire damage to the harness will result.
• If using a fast charge procedure, be sure to
disconnect the battery positive cable. If you do not,
the rectifier diodes will be exposed to high positive
voltage that will destroy them.
• Be very careful to reassemble the parts to thei
r
original positions. Particular care must be taken
with insulated parts.
• Carefully clean all insulated parts so that they are
completely free of oil and/or grease.
• Be sure that B-terminal twist-type stoppers (round
terminal) are securely inserted before tightening
the nuts.
Final Assembly
1. Use a bench press to install the rotor and rear
cover to the front cover.




RTW 56DSH000201

2. Install the pulley to the rotor shaft and tighten the
bolt to the specified torque.

Pulley bolt torque N
⋅m (kg⋅m / lb ft)
111 (11.3 / 81.7)





RTW 56DSH000101

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ISUZU KB P190 2007

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-15
Starter Motor
Starting Circuit Diagram



RTW 46DSH005501
Removal and Installation
Read this Section carefully before performing any
removal and installation procedure. This Section gives
you important points as well as the order of operation.
Be sure that you understand everything in this Section
before you begin.
Important Operations - Removal
Starter Motor
1. Disconnect the battery cable and the ground cable at the battery terminals.
2. Remove the A/T oil level gage.
3. Remove the Engine oil level gage.
4. Disconnect the magnetic switch cable at the terminal bolts.
5. Disconnect the battery cable at the starter moto
r
and the ground cable at the cylinder body.
6. Remove the starter motor from the engine.

Important Operations – Installation
Follow the removal procedure in the reverse order to
perform the installation procedure. Pay careful attention
to the important points during the installation procedure.

Starter Motor
1. Install the starter motor to the rear plate.
2. Tighten the starter motor bolts to the specified torque.
Starter Motor Bolt Torque N⋅m (kg ⋅m/lb ft)
85 (8.7 / 63)
3. Install the Engine oil level gage.
4. Install the A/T oil level gage.
5. Reconnect the battery cable at the starter moto
r
and the ground cable at the cylinder body.
6. Reconnect the battery cable and the ground cable at the battery terminals.



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