Isuzu KB P190. Manual — part 257

ENGINE ELECTRICAL 6D – 27

RTW46DSH003701

6. Use the circuit tester to check the armature for

continuity.

1

Hold the circuit tester probes against two
commutator segments.

2

Repear Step 1 at different segments of the
armature core.

There should be continuity between all segments of
the commutator.
If there is not, the armature must be replaced.

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YOKE

1. Use a circuit tester to check the field winding ground.

1

Hold one circuit tester probe against the field
winding end or brush.

2

Hold the other circuit tester probe against the bare
surface of the yoke body.

There should be no continuity.
If there is continuity, the field coil is grounded.
The yoke must be replaced.

RTW46DSH003901

2. Use the circuit tester to check the field winding

continuity.

1

Hold one circuit tester probe against the “M”
terminal lead wire.

2

Hold the other circuit tester probe against the field
winding brush.

There should be continuity.
If there is no continuity, the yoke must be replaced.

6D – 28 ENGINE ELECTRICAL

BRUSH AND BRUSH HOLDER

1. Use a vernier caliper to measure the brush length (four

brushes).
Replace the brushes as a set if one or more of the
brush lengths is less than the specified limit.

Brush Length

mm (in)

Standard Limit

15 (0.59)

12 (0.47)

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2. Use a circuit tester to check the brush holder

insulation.
Touch one probe to the holder plate and the other
probe to the positive brush holder.
There should be no continuity.

3. Inspect the brushes for excessive wear.

If the negative brushes have excessive wear, the
entire brush holder assembly must be replaced.
If the positive brushes have excessive wear, the entire
yoke must be replaced.

OVERRUNNING CLUTCH

1. Inspect the overrunning clutch gear teeth for

excessive wear and damage.
Replace the overrunning clutch if necessary.

2. Rotate the pinion clockwise.

It should turn smoothly.

3. Try to rotate the pinion in the opposite direction.

The pinion should lock.

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BEARING

Inspect the bearings for excessive wear and damage.
Replace the bearings if necessary.

ENGINE ELECTRICAL 6D – 29

REASSEMBLY

RTW46DLF000601

Reassembly Steps

1. Magnetic switch assembly

14.

Pinion stopper

2. Magnetic switch

15.

Pinion stopper clip

3. Dust cover

16.

Bearing retainer

4. Plunger

17.

Bolt

5. Torsion spring

18.

Motor assembly

6. Shift lever

19.

Armature

7. Gear case

20.

Yoke

8. Dust cover

21.

Brush holder

9. Bolt

22.

Rear

cover

10. Pinion assembly

23.

Screw

11. Clutch

24.

Through

bolt

12. Pinion shaft

25.

Lead wire

13. Rerurn spring

6D – 30 ENGINE ELECTRICAL

RTW46DSH005601

Important Operations

1. Magnetic Switch Assembly

1. Attach the torsion spring to the hole in the magnetic

switch as illustrated.

2. Insert the shift lever into the plunger hole of the

magnetic switch.

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7. Gear

Case

3,8. Dust Cover

1. Install the magnetic switch assembly in the gear case.
2. Install the dust cover.

Dust Cover Bolt Torque

N

⋅m (kg⋅m/lb⋅ft)

8 (0.8/5.4)

10. Pinion Assembly

Apply a coat of grease to the reduction gear and install the
pinion assembly to the armature shaft.

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21. Brush Holders

1. Install the brushes into the brush holder with raising

the spring end of the brush spring.
Take care not to damage the commutator face.

2. Install the brush holder with aligning the peripheries of

the yoke and the brush holder.