ALTERNATOR REPAIR/TEST - continued - TM-10-3930-673-340300

TM 10-3930-673-34

6-3. ALTERNATOR REPAIR/TEST (CONT)

b. Cleaning.

(1)

Clean brushes (47) using soft, dry cloth.

(2)

Clean slip rings on rotor assembly (9).

(a)

Place rotor assembly (9) in a lathe, with

slip ring of shaft free.

(b)

While rotor is spinning in lathe, hold No.

00 sandpaper or 400 grit silicon carbide

paper against slip ring (50) surface.

(c)

After polishing slip rings (50), clean

using low pressure (15 psi maximum)

compressed air.

c. Inspection.

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(1)

Inspect roller bearings (13 and 45) for rough

rotation or visible damage. Replace if faulty.

(2)

Inspect brushes (47) for excessive wear. Replace as needed.

(3)

Inspect brush springs (48) for distortion or discoloration. Replace as needed.

d. Testing.

(1)

Test diode trio (27).

(a)

Connect multimeter between diode trio

single connector (51) and each of the

other connectors (52,53, and 54) in turn.

Observe resistance reading.

(b)

Reverse multimeter leads, or reverse

meter polarity, and repeat STEP a, above.

(c)

At one polarity, resistance reading should

be low and at the other polarity, resistance

TR01430

reading should be very high, if diodes are

good. If both readings on same set of

connectors are either high or low, the

associated diode is faulty and entire diode trio must be replaced.

6-6