2007 ISUZU KB P190 engine

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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ISUZU KB P190 2007

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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ISUZU KB P190 2007

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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ISUZU KB P190 2007

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