Rotor Open or Short Test

NOTE: Alternator must be disassembled to conduct this test.

1. Use Rotunda 73 Digital Multimeter 105-00051, or equivalent, to measure resistance between two slip rings.
2. If resistance is not 3.5-4.5 ohms, replace rotor.
3. Check for continuity between each slip ring and rotor core.
4. If there is continuity, replace rotor.
5. Check slip ring color and condition.
6. If rings are dark, clean them with fine sandpaper.
7. If rings are grooved, refinish them on a lathe.