TM-9-2320-280-34

TRUCK, UTILITY: M998 SERIES

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

JANUARY 1996

TM-9-2320-280-34 - Page 350 of 1258

TM 9-2320-280-34

6-4.

200 AMPERE ALTERNATOR (A0013036AA) TESTING AND REPAIR (Cont ’d)

(c)

Reverse ohmmeter leads so the POSITIVE probe contacts the positive rectifier mount and the

NEGATIVE probe contacts each of the three rectifier leads. LOW resistance (zero or close to

zero) reading indicates defective rectifiers.

Mount must be replaced.

NOTE

Positive rectifiers are acceptacle if a LOW resistance reading is

noted in step 14.(b) and a HIGH resistance reading is noted in

step 14.(c) for each of the three rectifier leads.

(d)

Connect ohmmeter POSITIVE probe to a bare metal surface on the housing, and the NEGATIVE

probe to each of the three negative rectifier leads.

HIGH resistance for any of the three rectifier

leads indicates defective rectifiers.

Replace alternator.

(e)

Reverse test probes so NEGATIVE probe contacts the housing and the POSITIVE probe is

connected to each of the three rectifier leads.

LOW resistance indicates defective rectifiers.

Replace alternator.

NOTE

Negative rectifiers are acceptable if a LOW resistance reading is

noted for each rectifier lead in step 14.(d) and a HIGH resistance

reading is noted for each rectifier lead in step 14.(e).

15.

Perform stator ground test as follows:

(a)

Set ohmmeter to X10K scale and connect one probe to a bare metal surface on the housing and

the other probe to each of the three stator terminals.

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