TM-9-2320-280-34 HMMWV Direct Support & General Support Maintenance Manual Download
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6-5. 200 AMPERE ALTERNATOR (12338796-1) TESTING AND REPAIR (Cont'd) b. Disassembly 9. Regulator Bypass Test. NOTE Perform this test only when instructed from tables 6-A.7 and 6-B. (a) Prepare alternator as in full load test. NOTE Use jumper wire rated for 15 amps. NOTE Complete alternator disassembly is not required for static testing. 1. Remove voltage regulator (TM 9-2320-280-20). 1.1. Install core and shaft assembly (11) in soft-jawed vise and remove locknut (6), washer (5), and fan (4) from core and shaft assembly (11). Discard locknut (6). 2. Remove bearing bushing (3) from core and shaft assembly (11). 3. Remove three screws (20), lockwashers (21), and plate cover (19) from front housing (17). Discard lockwashers (21). 4. Scribe alignment marks on front housing (17), stator (9), and end housing (2). 5. Remove nine locknuts (7) from end housing (2) and stator (9). Discard locknuts (7). 6. Use puller to remove end housing (2) from stator (9). 7. Remove six locknuts (1) from rear rotor (24) on core and shaft assembly (11). Discard locknuts (1). 8. Use three 10-32 x 2-in. long machine screws as jacks in threaded holes on end plate of rear rotor (24). Gradually tighten screws to remove rear rotor (24) from core and shaft assembly (11). Remove rear rotor (24) and screws. NOTE Prior to removal, tag leads for installation. 9. Remove eight nuts (18) and disconnect two field and six phase leads (8) from diodes in front housing (17). 10. Remove nine locknuts (22) from front housing (17) and stator (9). Discard locknuts (22). 11. Remove front housing (17) from stator (9) by tapping lightly with a soft-faced mallet. CONNECT DISCONNECT DIAGNOSIS AMPS RISE AMPS FALL Alternator OK. See note. Replace regulator only if low AMPS (80-119)/low VOLTS (21-25) are indicated in table 6-A.7 and/or table 6-B. NO CHANGE NO CHANGE Alternator must be repaired. Refer to Static Testing. Table 6-C. Regulator Bypass Test. TM 9-2320-280-34 6-40 Change 1 (b) Disconnect alternator connector from regulator. With alternator spinning, use jumper wire and short pin A of connector to ground momentarily. Record results. (c) Amperage should rise within ± 10% of rated output with jumper wire connected and fall with jumper disconnected. Refer to Table 6-C, Regulator Bypass Test, for diagnosis. 10. Turn test stand master power switch and load switch to OFF. 11. Disconnect jumper wires from terminals on test stand and alternator.