Bench Testing: Notes
- Mount alternator on test stand. Make connections as shown in charging system wiring diagram. See Fig 1. Leave carbon pile disconnected. Ground polarity of alternator and battery must be same. Ensure battery is fully charged. Use a 30-500 ohm resistor between battery and terminal "L".
- Rotate alternator by hand in clockwise direction. Slowly increase alternator speed and observe voltage. If voltage is uncontrolled and increases to more than 16 volts, rotor field is shorted and/or regulator is defective. Shorted rotor field coil can cause regulator to become defective.
- If voltage is less than 16 volts, increase speed and adjust carbon pile to obtain maximum amperage output. Maintain voltage at 13 volts. If output is within 15 amps of rated output, alternator is okay. If output is not within 15 amps of rated output, replace alternator. See the ALTERNATOR SPECIFICATIONS at end of this article.