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Generator Output

  1. Ensure connections at battery and generator are clean and tight. Ensure generator, engine and body are properly grounded. Ensure generator drive belt is properly adjusted and in good condition.
  2. Connect load tester/ammeter as per tester manufacturer's instructions. Connect voltmeter leads to battery terminals. See Fig 1 . Start engine and run at 2200 RPM for V6 or 2500 RPM for V8. Adjust load tester to obtain maximum generator output. DO NOT allow voltage to drop to less than 12.7 volts.
  3. Maximum generator output should be within a few amps of generator rated output stamped on generator. If output is not within a few amps of generator rated output, check generator diodes. See DIODE TEST  . Replace generator as necessary.
    Fig 1: Checking Generator Output (Chassis 163)
    G00316820Courtesy of MERCEDES-BENZ OF NORTH AMERICA.