Fig.
5-10
Fig.
5-11
Fig.
5-12
Fig.
5-13
5
11. Rear bearing and front bearing
(if
necessary)
5-8-5.
Inspecting Alternator
a. Checking
stator
coil
Ground test:
Connect one prod to the core and the other
to
each
lead wire.
If
a ground
is
present, the current will flow
and the stator coil must be replaced.
Short
circuit test:
Connect the prods
to
each
of
the two leads.
If
there
is
no flow
of
current, the coil
is
open circuit ·and must
be replaced.
b. Checking
rotor
Ground test:
Connect one prod to
the
slip ring and other prod to
the core.
If
the current flows the rotor must be replaced.
Short
circuit test:
Place
both
prods
of
an ohmmeter on the slip rings.
If
the reading
is
3
to
6 ohms, there is
no
trouble
in
the
rotor.
c. Checking diode (rectifier assembly)
Diodes for
use
in the alternator are available in two
different types, the positive diode which allows current
to
flow from the lead wire
to
the case
but
not from
the case to the lead wire and the negative diode which
has the
opposit~
properties.
To check the diode, read the resistance between the
terminal and case with a tester. Then reverse the tester
leads and note the reading.
If
b'
oth
readings are very
low or high, the diode is defective.
A good diode will
give
one low reading and one high
reading.
Note:
The diodes and heat sink are serviced as rectifier
assembly only.
5 : 4
t
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