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 337 of 1258
TM 9-2320-280-34
6 - 1 8 . 3 2
Change 1
Table 6-A.3. No-Load Test.
Table 6-A.4. Full-Load Test.
AMPS
28 VDC
14 VDC
DIAGNOSIS
81-100
21-25
10.5-12.5
Test bench battery is discharged (or defective).
Allow to charge (or replace).
81-100
26-30
13-15
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.
81-100
31-35
15.5-17.5
STOP TEST. Regulator and/or tube assembly must
be replaced. Refer to static testing, task c.
40-59
21-25
10.5-12.5
Alternator and/or regulator must be repaired or
replaced. Refer to table 6-A.6.
40-59
26-30
13-15
Regulator OK. Refer to table 6-A.4.
40-59
31-35
15.5-17.5
STOP TEST. Test bench malfunction or wiring error.
AMPS
28 VDC
14 VDC
DIAGNOSIS
81-100
21-25
10.5-12.5
Test bench battery is discharged (or defective).
Allow to charge (or replace).
81-100
26-30
13-15
Charging system OK.
81-100
31-35
15.5-17.5
STOP TEST. Regulator and/or tube assembly
must be replaced. Refer to static testing, task c.
40-59
21-25
10.5-12.5
Alternator and/or regulator must be replaced.
Refer to table 6-A.6.
40-59
26-30
13-15
Increase load.
40-59
31-35
15.5-17.5
STOP TEST. Test bench malfunction or wiring
error.
NOT E
• When tachometer reaches 3000 rpm, green lamp should go off
indicating proper charging from alternator.
• Normal voltage range is 26-30 VDC. High amperage is +10 percent
over the rated alternator output of 81 amps at 5000 rpm.
9.
Perform full-load test. Ensure all load switches are in ON position on 500-amp test stand, and
increase alternator speed to 5000 rpm. Set load to 81 amps/min; record results. Refer to table 6-A.4,
Full-Load Test, for diagnosis.
6±-±3±
.±3±
. 100 AMPERE DUAL VOLTAGE ALT±E±R±N±ATOR (12447110) TESTING AND REPAIR (Cont’d)
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