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Regulator and Diode Test

  1. Disconnect regulator field lead (EX). Attach jumper wire from field terminal (EX) to output terminal (B+). See Fig 1. Turn ignition "ON", and run engine at fast idle speed.
    Fig 1: Checking Regulator and Diodes
    G09330232Courtesy of NOT AVAILABLE

    Attach jumper wire to field and output terminals  .

  2. Connect negative lead of voltmeter to ground and positive lead to output terminal (B+).
  3. If voltage rises to 14-16 volts in this test, but did not reach 14 volts in Output Voltage Test, regulator is defective.
  4. If output voltage does not rise, and field current has been proven satisfactory in Field Circuit Test and Additional Field Circuit Test, either alternator stator or the rectifier diodes are defective.