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