ALTERNATOR REPAIR/TEST - continued - TM-10-3930-673-340301

TM 10-3930-673-34

(2)

Test rectifier bridge assembly (21).

(a)

Connect multimeter from grounded heat

sink (55) to diode terminal (56) and note

resistance reading.

(b)

Reverse multimeter leads or reverse meter

polarity and again note resistance reading.

(c)

At one polarity, resistance reading should

be low and at the other polarity, resistance

reading should be very high, if diode is

good. If diode is faulty, both readings will

be either low or high.

TR01431

(d)

Repeat above sequence between

grounded heat sink (55) and diode terminals (57 and 58), and then between insulated heat sink (59) and each

diode terminal (56, 57 and 58).

(e)

If any set of readings indicates a faulty diode, replace complete rectifier bridge (21).

(3)

Test rotor assembly (9) for short of open

circuits.

(a)

Connect multimeter between slip rings

(50), in turn, and rotor shaft (60)

(connection A). Observe resistance

reading on ohmmeter.

(b)

Resistance reading should be high

(infinite). If not, rotor (9) is defective and

must be replaced.

(c)

Connect multimeter leads across slip

rings (50) (connection B). Observe

resistance reading on ohmmeter. A high

(infinite) resistance reading indicates an

TR01432

open rotor winding and rotor (9) must be

replaced.

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