Datsun 1000 Workshop Manual page 154

Electrical
Sysrem 8
LOCK WASHER
FAN
DRIVE END BRACKET
RETAINING SCRE
k
ROTOR
SLIP RINGS
PULLEY HALF
I
NI
OP
t
WASHER
BEARING
S
Hitachi L T125 02 Alternator
STATOR WINDINGS
TO
CHECK AND
TEST COMPONENT PARTS
All parts
being electrically
tested should be
resting on a
non
conductive pad
Slip Rings
I Visually
check the
slip ring assembly
for
damage
2 Remove
all burrs and burn
marks
with fine sand
paper
not
emery
paper
3 With
a
110 volt AC test
lamp
and prods test the
slip ring
unit
for
an
electrical bridge between
the
slip rings
The test
lamp
should
not light
NOTE The above
test
is carried
out
with the
field
leads
disconnected
4 If the
test lamp lights
up
or
burns
dimly indicating
an
electrical bridge
a new
slip ring assembly will have
to
be
fitted
5
Using
a
110
volt
AC
test
lamp and prods
check the
slip ring
to
earth insulation by
holding
one
prod
on
the
rotor
shaft and
touching
the other prod
to
each slip ring
in
turn
6
If
the test lamp lights
up
or
burns dimly indicating
an
electrical
short
a new
slip ring assembly
will have
to
be
fitted
Field
Windings and Rotor Assembly
I
The insulation
to
earth test is done with the 110
volt
test
equipment
connect one
of
the test
prods to
one
of
the field
wires and the other test
prod
to one
pole piece
of
the
rotor
2 If the
test lamp lights
or
burns dimly and
no
visual
earthing
can
be
seen
and rectified
a new
rotor assembly
will have
to
be fitted
3 To check for
bridged
or
internal
shorting
of
the
field coil
connect a
pair of
test
leads
to
a
12
volt battery
with
an
ammeter
connected in series with
one
lead
connect
CUP FELT SEAL
I
I
o
0
RETAINER
C
BRUS
END BRACKET
NAL NUTS WASHERS
AND INSULATORS
I
lit
0
o
Q
00
C C
o
C
t I
04
SCREWS
0
BRUSH COVER
I
COVER SCREWS
o
the test leads
one
to
each field wire and note the ammeter
reading
a
high reading
over
3 5 amps
indicates
a
bridged
circuit within the
coil
No reading
on
the armf1eter indicates
an
open circuit exists in the
field
coiL
In both the
above
cases a new
rotor
assembly
will have to be fitted
Stator
Windings
I
The insulation to
earth
test is
done
with the 110
volt test
equipment
connect
one
test prod to
one
stator
wire
and
the other
test
prod to
the
laminated
stator
winding
frame
2 If the
lamp
lights
or
burns dimly indicating
a
short
circuit
a
new
stator
windil
g
assembly
must
be fitted
3 To test the
continuity
of the
stator
winding
connect
a
pair
of
test
leads
to
a
12 volt
battety
connect in
series with
one
of the leads
a
36 watt
globe
4 Connect the test leads across any two leads
of the
stator
winding
the
lamp
should
light
Repeat
the
operation
to the
remaining leads alternately
5
If
the
light fails
to
light
on anyone
of the
tests
then
the
stator
winding assembly
will have to be renewed
Diodes
Models LTI2S 02 and AS202SA
1
CA UTION Never
use
a
hand driven
generator type
tester
to test
diodes
Before
the
diodes
can
be tested the
wiring
has
to
be
unsoldered from
the
diode leads using
a
very
hot soldering
iron and holding the
diode lead with
a
pair
of
pointed pliers
to
dissipate the
heat
and
protect
the diode unsolder each
wire in turn
after
marking
and
noting
their
connected
positions
Connect
a
pair
of
test
leads
to a
12 volt
battery
with
a
1
5
walt
globe in series with
one
lead touch the diode wire
with
one
lead and
the
heat sink of that diode with the other
lead then
reverse
the leads
155