Testing Alternator Internal Field Circuit For A Ground; Inspection; Testing Rectifiers (Positive) - Piper Cherokee Six Service Manual

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