Field Open Or Short Circuit Test
- Set ohmmeter on "x1" scale. Contact one probe to alternator FLD terminal and connect other probe to GND terminal. Spin alternator pulley.
- Ohmmeter should read between 2.4-100 ohms and should fluctuate while pulley is spinning. An infinite reading indicates grounded brush lead, worn or stuck brushes, or bad rotor assembly.
- A reading of less than 2.4 ohms indicates grounded brush assembly, grounded field terminal, or a bad rotor.