Subaru 1600 Service Manual page 680

Housing
Bushing
"-
Measuring diameter
A9-022
Fig. 15-23 Measuring diameters
b. Inspect the surface of the com·
mutator and correct with emery
cloth (No. 500) when it is rough_
If considerably rough, correct by
using a lathe.
Replace the armature if the outer
diameter of the commutator be-
comes less than the specified limit.
If there is oil on the surface, clean
off with gasoline.
)}}n~
- 30.7mm
(1.209 in)
A9-023
Fig. 15-24 Commutator outer
diameter
Commutator outer
diameter minimum
limit
30.7mm
(1.209
in)
When the out-of-round of the com·
mutator exceeds the limit, correct.
Limit 0.4 mm (0.016 in)
Out-of-
round
Standard
0.05 mm (0.0020 in)
or less
c. Measure the depth of the top
surface of each mica from the com-
mutator surface, and correct if it
exceeds the limit.
Depth
Limit 0.2 mm (0.008 in)
of
0.5 - 0.8 mm
mica
Standard
(0.020 - 0.031
in)
ELECTRICAL SYSTEM
Segment
Mica
A9·024
Fig. 15-25 Undercut dimension of
the commutator
NOTE:
When the commutator outer diameter
is corrected, make sure the depth of
the top surface of each mica is 0.5 mm
to 0.8 mm (0.020 to 0.031 in).
d. Armature coil insulation test
Test the insulation between the
core and commutator segments,
and between the commutator seg-
ments and shaft. Repair or replace
whenever the insulation is defective.
A9-025
Fig. 15-26 Armature coil insulation
test
e. Layer short test of armature coil
Place the core of the armature coil
on a growler tester, apply an iron
piece (hack-saw blade, etc.) to the
core surface, and rotate the arma·
ture slowly.
If the iron piece vibrates and is
attracted, there is a short circuit
between the coils or between com-
mutator segments.
Repair or replace.
Iron sheet
Growler tester
Fig. 15-27 Layer test of armature coil
15-17
f. Test for open armature coil
Check armature for continuity be·
tween two segments side by side.
If the tester shows no continuity
the circuit is open.
Repair or replace.
A9·027
Fig. 15-28 Open-circuit test for
armature coil
• Field coil
a. Insulation test of field coil
Check the insulation between the
field coil (+) terminal and yoke.
If tester shows continuity, remove
the pole cores one by one, locate
the grounded part, and repair or
replace.
A9-02B
Fig. 15-29 Field coil insulation test
b. Test for open field coil
Using a circuit tester, check the
field coil for continuity, and re-
place if open.
c. Check the resistance between the
connecting lead wire and the sold-
ered parts of the brush lead wires.
The resistance should be almost
zero ohm.
Fig. 15-30 Field coil resistance test