TM-9-2320-387-24 HMMWV Direct Support & General Support Maintenance Manual Volume 2 Download
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Th49-2320-387-24-2 18-3. ILOO-AMPERE DUAL VOLTAGE ALTERNATOR TESTING AND REPAIR (Cont’d) NOTE l When tachometer reaches 3,000 rpm, green lamp should go off indicating proper charging from alternator. l Normal voltage range is 26-30 VDC. High amperage is +lO percent over the rated alternator output of 182 amps at 5,000 rpm. 10. Perform no-load test. Increase alternator speed to 5,000 rpm; record results. Refer to table 18-1 for diagnosis. 11. Perform full-load test. Ensure all load switches are in ON position on 500-amp test stand, and increase alternator speed to 5,000 rpm. Set load to 182 amps/mm, record results. Refer to table 18-2 for diagnosis. Table 18-1. No-Load Test. AhdPS(28v) 28V VOLTS 14v 161-200 21-25 10.5-12.5 161-200 26-30 13-15 161-200 31-35 15.5-17.5 80-119 21-25 10.5-12.5 80-119 26-30 13-15 80-119 31-35 15.5-17.5 IPS (28V) 161-200 28V VOLTS 14v ! DIAGNOSIS 21-25 10.5-12.5 161-200 26-30 13-15 161-200 31-35 15.5-17.5 80-119 21-25 10.5-12.5 80-119 26-30 13-15 80-119 31-35 15.5-17.5 C DIAGNOSIS Test bench battery is discharged (or defective). Allow to charge (or replace). 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 systems OK STOP TEST. Regulator and/or tube assembly must be replaced. Refer to static testing, task c. Alternator and/or regulator must be repaired or replaced. Refer to table 18-3. Regulator OK Refer to table 18-2. STOP TEST. Bench malfunction or wiring error. Table 18-2. FullLoad Test. ‘Ikst bench battery is discharged (or defective). Allow to charge (or replace). Charging system OK STOP TEST. Regulator and/or tube assembly must be replaced. Refer to static testing, task c. Alternator and/or regulator must be replaced. Refer to table 18-4. Increase load. STOP TEST. Test bench malfunction or wiring error. 18-4