Isuzu KB P190. Manual — part 400

6D-12 ENGINE ELECTRICAL (4JK1/4JJ1)

4. Check for conductivity between the slip rings and

the rotor core. If there is continuity, the rotor

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

0.07

Ω 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

M

Ω

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)

066RW024

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-13

Rectifier

Measure each of the diode resistances in both
directions (anode/cathode and cathode/anode). If any of
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.

RTW56DMF000301

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 rectifier

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 their

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.

RTW56DSH000201

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)

RTW56DSH000101

ENGINE ELECTRICAL (4JK1/4JJ1) 6D-15

Starter Motor

Starting Circuit Diagram

RTW46DSH005501

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 motor

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 motor

and the ground cable at the cylinder body.

6. Reconnect the battery cable and the ground cable

at the battery terminals.