Subaru 1600 Service Manual page 688

A9·251
Fig. 15·73 Broken wire test in rotor
coil
3) Insulation test
Inspect continuity between slip
ring and rotor core. If continuity
exists, replace rotor assembly because
rotor coil or slip ring is broken.
A9-252
Fig. 15-74 Insulation test of rotor coil
4) Check the ball bearing and replace
if defective.
2) Stator
1) Broken wire test
Inspect the stator coil for continui-
ty between its terminals.
When there is no continuity
between individual terminals, the cable
is broken.
Replace stator assembly.
A9·253
Fig. 15-75 Stator coil broken wire
test
2) Insulation test
Inspect the stator coil for conti-
nuity between the stator core and the
each terminal. If there is continuity,
stator coil is grounded.
ELECTRICAL SYSTEM
A9-25d
Fig. 15-76 Stator coil insulation test
3) Brush
1) Inspect the movement of the
brush and if the movement is not
smooth, check brush holder and clean
it.
Check brush for wear. If it is worn
out to less than specified limit, replace
brush assembly.
Brush wear_
'-jIc~-
A9·255
Fig. 15-77 Brush wear limit
2) With brush protruded approxi·
mately 2 mm (0.08 in) from brush
holder, measure brush spring pressure
with a spring balance.
Nonnally the pressure of a new brush
spring is 255 to 345 g (8.99 to 12.17
oz). When brush is worn, pressure
decreases approximately 20 g (0.71 oz)
per 1 mm (0.04 in) wear.
2 mm (0.08 in)
A9·256
Fig. 15-78 Measuring spring pressure
15-25
4) Diode Assembly
Perform a continuity test on diodes
in both directions, using an ohmmeter.
A total of six diodes are used, there
are mounted on the positive (+) plate,
and other three arc on the negative (-)
platr.
1
he continuity test should be
performed on each diode between
the terminal and plate.
O;ode
®
plate
. .. rr
r.
,Diode
8
plate
CondIJct;v~
,
'I ~'
d"''''O''/=~l
!fY
>O'"do
,,; c:
II,
-11
I
, q
1/
G r
Fig.
15-.79 Direction of diode
conduction
Fig. 15-80 Diode assembly
A9·066
A9·257
A9·258
Diodes installed on (+) plate are
positive diodes which allow current
flowing from terminal to (+) plate
only.
Diodes installed on (-) plate are
negative diodes which allow current
flowing from (-) plate to terminai
only. If each current flows in the
same direction only, the diode is in
good condition.
If current flows toward both
positive and negative directions, the
diode is short circuited. In this case,
replace diode assembly.