18-3.1. 400-AMPERE DUAL VOLTAGE ALTERNATOR TESTING AND REPAIR (Cont'd)
Perform regulator bypass test. Prepare alternator as in full-load test.
Perform this test only when instructed from tables 18-5 and 18-6.
Use jumper wire rated for 15 amps.
Disconnect alternator connector from regulator. With alternator spinning, use jumper wire and
short pin A to ground momentarily. Record results.
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.
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.
Alternator must be repaired. Refer to static
testing, task c.
Table 18-8. Regulator Bypass Test.
Turn test stand master power switch and load switch to OFF.
Disconnect jumper wires from terminals on test stand and alternator.
Remove belt from test stand pulley and alternator pulley. Remove alternator from test stand.