Piper Cherokee Six - Testing Alternator Internal Field Circuit for a Ground; Inspection; Testing Rectifiers (Positive)

10-7.
TESTING ALTERNATOR
INTER-
NAL FIELD
CIRCUIT FORA
GROUND.
To
test
the
alternator
internal
REMOVED
field circuit
for a short
circuit
to
ground,
proceed
as
follows:
Remove the
ground brush and
using
a 110
volt
test lamp,
place
one
test
probe
to the field
terminal
and the
remaining test probe to a machined sur-
face
at one
of the alternator
end shields
.
(Refer to
Figure
10-5.)
The test
lamp
should not
light.
Figure 10-5.
Testing
Field Circuit
If the test
lamplights,
carefully
observe
the order
in which
the parts were
installed
as you remove
the insulated
brush
assembly.
Remove
the three
through bolts.
Then,
separate the
two end
shield
assemblies.
Touch
one
of the
test lamp
probes
to
one of
the slip
rings
and
the
remaining
test
probe
to the rotor
shaft.
The
lamp should
not
light. If
the
lamp lights,
the rotor
assembly
is grounded
and
requires
replacement.
If
the test
lamp does
not light,
the ground
condition
was in the
insulated
brush assemblvand
theparts
were
either assembled
wrong
or damaged
and short
circuiting
through tog-round.
Inspect
the brush
holder
and insulatedwasher.
Re-
place if
damaged.
The stack
of parts
attaching
the
insulated
brush
holder assen--
blv to
the end
shield must
aiwavs
be installed
in
the proper
sequence
as
follows:
Insulated
brush
holder,
"FLD"
terminal,
insulating
washer,
lockwasher
and at-
taching screw.
10-8. INSPECTION. Inspect
the condition of the alternator
components paving
special
attention
to the
condition
of the
slip rings
for indications
of oil,
being
burnt
or worn.
Inspect
brushes
for
signs of
sticking
in holder
or shield
and for
wear.
Inspect
the
bearing
surface
of
the rotor
shaft
and
the
roller
bearings
at
the rectifier
end.
Rotate
the rotor
in the
drive
end shield
to feel
for roughness
in the
drive
end bearing.
Inspect
the
grease
retainer,
if so
equipped,
on late
alternators.
Inspect
the
rectifier
leads especially
at connections
for
a good
sol-
der
joint, also
inspect insulation.
Rectifier/stator
lead must
be pushed
down in-
to the slots
that are
cast into
the end shield
and cemented
with
MoPar Cement
#2299314.
10-9. TESTING
RECTIFIERS
(POSITIVE).
(Refer to Figure
10-6.) Special
test
box
tool C-3829
has been
developed
to test the
diode rectifiers
without
opening
ELECTRICAL
SYSTEM
Issued:
8/17/72
PIPER CHEROKEE
SIX SERVICE
MANUAL
3A23