Alternator Output
- Mount alternator on a test stand. Make connections as shown in charging system bench testing diagram. See Fig 1. Turn off carbon pile. Test battery must be fully charged. Ground polarity of alternator and battery must be the same. Use a 30-500 ohm resistor between battery and terminal "L".
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- 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. A shorted rotor field coil can cause the regulator to become defective.
- If voltage is less than 16 volts, turn on carbon pile, increase speed and adjust carbon pile to obtain maximum amperage output. Maintain voltage greater than 13 volts. If output is within 15 amperes of rated output, alternator is okay. If output is not within 15 amperes of rated output, service or replace alternator. Refer to the ALTERNATOR OUTPUT SPECIFICATIONS .