TM-9-2320-387-24 HMMWV Direct Support & General Support Maintenance Manual Volume 2 Download
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18-3.1. 400-AMPERE DUAL VOLTAGE ALTERNATOR TESTING AND REPAIR (Cont'd) TM 9-2320-387-24-2 Change 1 18-10.7 26. Perform regulator bypass test. Prepare alternator as in full-load test. NOTE • Perform this test only when instructed from tables 18-5 and 18-6. • Use jumper wire rated for 15 amps. 27. Disconnect alternator connector from regulator. With alternator spinning, use jumper wire and short pin A to ground momentarily. Record results. 28. Amperage should rise within ±10 percent of rated value with jumper wire connected, and fall with jumper disconnected. Refer to table 18-8, Regulator Bypass Test, for diagnosis. CONNECT DISCONNECT DIAGNOSIS AMPS RISE AMPS FALL Alternator OK. Replace regulator only if low AMPS (160-238)/low VOLTS (21-25) are indicated in table 18-5 and/or table 18-6. NO CHANGE NO CHANGE Alternator must be repaired. Refer to static testing, task c. Table 18-8. Regulator Bypass Test. 29. Turn test stand master power switch and load switch to OFF. 30. Disconnect jumper wires from terminals on test stand and alternator. 31. Remove belt from test stand pulley and alternator pulley. Remove alternator from test stand.