Regulator and Diode Test

Disconnect regulator field lead (EX). Attach jumper wire from field terminal (EX) to output terminal (B+). See Fig 1. Turn ignition to "ON" position. Run engine at fast idle speed.

Fig 1: Checking Regulator and Diodes Attach jumper wire to field and output terminals.
Connect negative lead of voltmeter to ground and positive lead to output terminal (B+). If voltage rises to 14-16 volts, but did not reach 14 volts in Output Voltage Test, regulator is defective.
If output voltage does not rise, and field current tested as good in Field Circuit Test, either alternator stator or rectifier diodes are defective.