Stator Winding Test

Turn ignition switch to "OFF" position. Using a voltmeter, check voltage on any of the 3 phases of stator windings, accessible through ventilation holes.
Connect voltmeter negative lead to ground and positive lead to phase winding. See Fig 1. Voltmeter should indicate zero (0) volts.

Fig 1: Checking Voltage Between Stator Windings and Ground Insert voltmeter positive probe through ventilation hole.
Connect negative lead to phase winding, and positive lead to output terminal (B+). See Fig 2. Voltmeter should read zero (0) volts.

Fig 2: Checking Voltage Between Stator Windings & Alternator Positive Terminal Insert negative probe through ventilation hole.
Any reading other than zero (0) volts in steps 2) and 3) indicates a defective positive rectifier diode. Replace diode bridge.