connect the test voltmeter, replace the 40 amplere fuse
and reassemble the rear plate to the housing with 3 self
tapping screws.
14-10. Disassembly, Cleaning and Inspection.
a. Disassembly.
See figure 14-2 and disassemble
the battery charging alternator as illustrated.
b. Cleaning. Blow out all dirt from inside and wipe
interior and exterior surfaces with a clean dry cloth.
c. Inspection. Inspect all components of alternator
assembly for heat damage, excessive wear, broken parts,
and corrosion.
(1) Inspect bearings for rough motion or
seizure.
(2) Inspect housing for distortion or cracks.
d. Diodes. Inspect diodes. Perform following check
with multimeter.
(1) With multimeter on RXl scale, check
continuity in opposite direction. This check should show
a resistance of less than 20 ohms in one direction and
OPEN CIRCUIT in the reverse direction.
(2) A high resistance or low resistance in both
directions indicates a defective diode. Replace a defective
diode.
e. R o t o r.
(1) Inspect rotor shaft for scoring and
distortion.
shall be
f.
(2) Test rotor for short circuits using a growler.
(3) Check rotor resistance. Resistance value
11 to 14 ohms.
Field Assembly
(1) Inspect field assembly case for cracks or
distortion.
(2) Inspect for openings in insulating
materials.
(3) Check resistance with ohmmeter.
Resistance value shall be approximately one ohm.
(4) Minimum insulation resistance (one
terminal to ground) shall be one megohm.
g. Voltage Regulator
(1) Inspect voltage regulator for cracks,
broken leads or other physical damage.
(2) Perform the following tests for the voltage
regulator. See figure 14-3.
(a) Connect the positive lead of an ohmmeter
to the yellow lead of the voltage regulator and check
resistance to the red lead of the voltage regulator. The
correct resistance is 600 to 900 ohms.
(b) Connect the positive lead of an ohmmeter
to the red lead of the voltage regulator and check
resistance to the yellow lead of the voltage regulator.
The resistance should infinite. Replace voltage regulator
if it fails inspection and/or tests.
h. BrushAssembly.
(1) Inspect for excessive wear, broken leads,
dirt and electrical requirements.
(2) Check brush spring tension. Tension
should be 4 to 6 ounces to move brush against spring.
(3) Check assembly for excessive wear.
Replace if 3/16 or less extends beyond bottom.
(4) Insulation test, point E to A, B, C, D, no
circuit, indicate no short circuit, assembly correct. See
figure 14-4.
(5) Continuity test, point A to B and C to D,
continuous circuit indicates no open circuit, assembly
correct. See figure 14-4.
14-11 Repair.
a. Diodes. Discard and replace defective diodes.
b. Rotor.
(1) Smooth minor scratches, burrs, and dents
on shaft with fine mill file.
(2) If shaft is bent or rotor is beyond repair,
replace defective battery charging alternator rotor.
c. FieldAssembly.
(1) Repair insulation damage with air-dry
varnish.
(2) Smooth minor scratches, burrs, and dents
on machined surfaces of case with fine mill file.
(3) If field assembly is beyond repair, replace
defective battery charging alternator field assembly.
14-12. Reassembly, Test and Installation.
a.
Reassembly. See figure 14–2 and reassemble
battery charging alternator except for cover assembly.
NOTE
After installation of pulley nut, see figure 14-2,
torque nut (item 33) to 40–50 foot pounds.
b. Tests See figure 14–3 and perform the
following tests:
(1) Remove black leads from negative terminal.
(2) Set ohmmeter to RX1 scale. Connect posi-
tive lead to regulator positive stud.
(3) Connect negative ohtnmeter lead to
negative stud.
(4) Ohmmeter should indicate 30 to 40 ohms.
(5) Reverse ohmmeter leads. Ohmmeter
should read infinity.
(6) Re–install cover assembly.
c.
Installation
Refer to the Operator and Organ–
izational Maintenance Manual and install the battery
charging alternator.
14-4 Change 11
