TM 9-2320-280-34
6-3.2. 100 AMPERE ALTERNATOR (12342944) TESTING AND REPAIR (Cont'd)
6.
Perform no-load test. Set test stand battery circuit selector to 24 VDC, IGN switch to ON, and start
varidrive. Observing the DC voltmeter output voltage and tachometer rpm, increase speed until
tachometer reads 5000 rpm. Record voltmeter reading and refer to table 6-A for diagnosis.
Table 6-A. No-Load Test.
AMPS
VOLTS
DIAGNOSIS
High
Low
Test bench battery is discharged (or defective).
Allow to charge (or replace).
High
Normal
Give time to stabilize while monitoring VOLTS.
If VOLTS rise above normal range (26-30 volts),
regulator and/or tube assembly must be replaced.
If AMPS fall, charging system is OK.
High
High
STOP TEST. Regulator and/or tube assembly must
be replaced. Refer to Static Testing.
Low
Low
Alternator and/or regulator must be repaired or
replaced. Refer to table 6-A.2.
Low
Normal
Regulator OK. Refer to table 6-A.1.
Low
High
STOP TEST. Bench malfunction or wiring error.
Change 1
6-18.17
