Rotor Open Or Short Test
- Remove rotor from alternator. Set ohmmeter knob to "X1" and calibrate. Contact each ohmmeter probe to a rotor slip ring. Meter reading should be 2.0-3.9 ohms.
- A higher reading indicates a damaged slip ring, welded connection or a broken wire. A low reading indicates a shorted wire or slip ring. Replace rotor if damaged.
- Contact one ohmmeter probe to a slip ring and the other probe to the rotor shaft. Meter reading should be infinite. A reading other than infinite indicates rotor coil is grounded to shaft. Replace rotor if grounded.