Checked diodes in alternator using a Fluke 88... when connected to alternator's "B+" and ground, obtained a reading of approx. 0.384 volts. Same test on a new rebuilt Bosch alternator yielded 0.949 volts. Additional diode testing using the Fluke's beep mode confirms the presence of diodes that are shorted (or have resistance of less than 4 Kohms), which also explains the concurrent loss of the instrument cluster warning lights.


So the question is now... did the replacement of the voltage regulator precipitate the diode failure or was it merely fortuitous the diodes failed shortly after the regulator's installation?

The instrument cluster warning lights were functional for a period of time after the regulator was renewed. In a perfect world, should one scope the alternator's output, prior to regulator renewal, to check for spurious wave forms that might indicate impending diode failure?