Rectifier Assembly Test
- Check rectifier assembly for poor solder joints, cracks, or signs of overheating. Clean small area of coating from each diode location to assure good electrical contact during testing.
- Using an ohmmeter, connect positive test probe to negative diode and negative probe to stator terminal. Ohmmeter should read 7-11 ohms resistance. Move positive test probe to positive diode, no continuity should be detected. See Fig 1. Perform same test procedure on each stator terminal to diode set.NOTE: 75HS alternator has 3 sets of diodes. 90HS and 120HS alternators have 4 sets of diodes.
- Connect negative ohmmeter probe to positive diode and positive probe to stator terminal. Ohmmeter should read 7-11 ohms resistance. Move negative test probe to negative diode, no continuity should be detected. Perform same test procedure on each stator terminal to diode set. If rectifier does not test as specified, replace rectifier assembly.