TM-9-2320-361-20

2-1/2-TON, 6x6, M44A2 SERIES TRUCKS (MULTIFUEL)

TECHNICAL MANUAL; UNIT MAINTENANCE

OCTOBER 1991

TM-9-2320-361-20 - Page 185 of 1207

TM 9-2320-361-20

Table 2-4. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 7. Check voltage regulator stability by varying engine speed.

a.

Decrease engine speed to 1000 rpm with headlights on. Regulated battery voltage

should remain at 28.0 ± 0.2 Vdc.

If battery voltage drops below 27.5 Vdc, do not repair 25 amp charging system. Replace

with 60 amp alternator conversion kit 11647745 (para. 4-3).

b.

e.

f .

g.

Increase engine speed to 2000 rpm with headlights on. Regulated voltage should remain

at 28.0 ± 0.2 Vdc.

If battery voltage increases above 28.5 Vdc, replace 25 amp charging system with

60 amp alternator conversion kit 11647745 (para. 4-3).

Return engine speed to 1200 rpm.

Turn headlights OFF and ON and observe change in battery voltage.

If battery voltage changes more than ± 0.5 Vdc and does not return quickly to

28.0 ± 0.2 Vdc, replace 25 amp charging system with 60 amp alternator conversion kit

11647745 (para. 4-3).

END OF TESTING!

c.

d.

2-100