Cs Series
- Mount alternator on a test stand. Make connections as shown on charging system wiring diagram. See Figure. Leave carbon pile disconnected. Ground polarity of alternator and battery must be the same. Battery must be fully charged. Use a 30-500 ohm resister between battery and terminal "L".
- Slowly increase alternator speed and observe voltage. If voltage is uncontrolled and increases to above 16 volts. Rotor field is shorted, regulator is defective, or both conditions exist. A shorted rotor field coil can cause the regulator to become defective.
- If voltage is lower than 16 volts, increase speed and adjust carbon pile to obtain maximum amperage output. If output is within 15 amperes of rated output, alternator is okay. If output is not within 15 amperes of rated output, replace alternator.
Courtesy of GENERAL MOTORS CORP