Isuzu KB P190. Manual - part 898

Charging System – V6 

Page 6D1-1-5 

 

• 

Death or injury to other people in or near the workplace area, and / or 

• 

Death or injury to the driver / or passenger(s) of the vehicle or other people, if the vehicle has been improperly 
repaired. 

CAUTION defined 

A CAUTION statement immediately precedes an operating procedure or maintenance practice which, if not correctly 
followed, could result in damage to or destruction of equipment, or corruption of data. If a CAUTION statement is 
ignored, the following consequences may occur: 

• 

Damage to the vehicle, 

• 

Unnecessary vehicle repairs or component replacement, 

• 

Faulty operation or performance of any system or component being repaired, 

• 

Damage to any system or components which depend on the proper operation of the system or component being 
repaired, 

• 

Faulty operation or performance of any systems or components which depend on the proper operation or 
performance of the system or component under repair, 

• 

Damage to fasteners, basic tools or special tools and / or 

• 

Leakage of coolant, lubricant or other vital fluids. 

NOTE defined 

A NOTE statement immediately precedes or follows an operating procedure, maintenance practice or condition that 
requires highlighting. A NOTE statement also emphasises necessary characteristics of a diagnostic or repair procedure. 
A NOTE statement is designed to: 

• 

Clarify a procedure, 

• 

Present additional information for accomplishing a procedure, 

• 

Give insight into the reasons for performing a procedure in the recommended manner, and / or 

• 

Present information that gives the technician the benefit of past experience in accomplishing a procedure with 
greater ease. 

 

1.3 System 

Operation 

Operation 

With the ignition switch in the ON position and the engine at rest, current is supplied via the regulator to generator 
connector E-4 pin 1 and to the engine control module ECM connector E-60 pin 43. This initiates current flow (within the 
regulator) from the generator connection P-9, to the brushes and rotor winding, to ‘excite’ the circuit. 

The current in the rotor winding creates magnetic fields between adjacent rotor poles. 

With the engine running, the rotor spins, the stator windings cut through this field and induce voltage. As the engine 
speed is increased, this induced voltage increases. Current then flows through the three-phase diode bridge in the 
rectifier to convert the AC voltage to DC. This is supplied to the generator connector P-9 output and then to the battery 
terminal via fuse SBF1. 

The regulator monitors the voltage to the battery. When this voltage reaches approximately 14.5 V, the regulator opens 
the circuit through the rotor winding, causing the generator output voltage to drop. When the regulator senses a voltage 
below a preset voltage, the regulator closes the circuit through the rotor winding and voltage to the battery again 
increases. This cycle repeats very rapidly. 

Charging System – V6 

Page 6D1-1-6 

 

Alternator Warning 

N O T E  

All generator faults are displayed as 

 

Check Alternator Warning on the instrument 
cluster MFD, refer to 8A Electrical Body and 
Chassis. 

The ECM monitors the voltage on connector E-60 pin 21 and pin 43. 

The voltage at the generator connector E-4 pin 2 will remain low when a fault condition is detected in the generator or 
associated external circuits. The voltage remains low (while the ignition switch is on) until the fault is repaired. 

N O T E  

For more information on the alternator warning 
refer to 8A Electrical Body and Chassis. 

Fault conditions include the following: 

• 

open circuit or excessive voltage drop in circuit 1, 

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open circuit in the generator phase connection, 

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overcharging conditions, 

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short circuit in the regulator output stage, 

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open circuit in the rotor winding, 

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poor contact between the rectifier and the regulator, and / or 

• 

high resistance in the fusible link assembly. 

Charging System – V6 

Page 6D1-1-7 

 

2 Diagnosis 

2.1 

Diagnostic General Information 

Basic Diagnostic Tools Required 

 

Use of incorrect electrical circuit diagnostic 
tools when performing the generator 
diagnostic procedures could result in 
incorrect diagnostic results or damage to 
components. 

The following electrical circuit testing tools are required to perform the diagnostic procedures detailed in this Section:  

• 

digital multimeter with 10 mega ohms impedance, and 

• 

connector test adapter kit Tool No. KM609. 

For further information on the use of these tools, refer to 8A Electrical Body and Chassis. 

2.2 

Tech 2 Data List 

The Tech 2 displays the status of certain charging system parameters. 

To view the data list: 

1 

Connect Tech 2 to the DLC. 

2 

On Tech 2 select: 
Engine / V6 Engine / Data Display / Data List / Electrical/Theft Data. 

Tech 2 Parameter 

Units Displayed 

Typical Display Values

Alternator L Terminal D 

Percentage 

Various 

2.3 

Diagnostic Systems Check 

Step Action 

Yes 

No 

1 

1 

Connect Tech 2 to the DLC. 

2 

Ignition ON, engine OFF. 

3 

On Tech 2 select: 
Engine / V6 Engine / Diagnostic Trouble codes / Read 
DTC’s. 

Are there any set DTC’s? 

Go to the 

appropriate DTC 

table in 6C1-2 

Engine 

Management – V6 – 

Diagnostics. 

Refer to 2.5

 Charging 

System Inoperative 

/ Malfunctioning 

 

Reference to following information will assist when diagnosing charging circuit faults: 

• 

for battery testing, refer to 6D1-3 Battery – V6, 

• 

for wiring diagram details, refer to Figure 6D1-1 2, and 

• 

for electrical component locations, refer to 8A Electrical Body and Chassis. 

Charging System – V6 

Page 6D1-1-8 

 

2.4 Wiring 

Diagram 

 

Figure 6D1-1 2