Testing C3 Voltage Regulators

[toobroketoretire]

Several years ago I made an ohm check of a new aftermarket C3 voltage regulator to show you the ohm values. Since then I discovered an AC Delco regulator has double the values but when you check a voltage regulator and find any of the values are ZERO (open) it's shot. I suggest you copy this picture and keep it in your files for future reference.

 

[Antz81]

Not sure how good this chart really is, as there are polarity sensitive components and other components which can fail without effecting those results in the regulator.

 

[toobroketoretire]

A "quick and dirty" test is turning your key ON and see if the rear alternator bearing has become highly magnetized. If so your voltage regulator is working because the rotor has become energized but it doesn't tell you if your voltage regulator is able to correctly adjust the output voltage. When working correctly it should limit the output voltage from 13.8 to 14.2 volts but that can vary a few tenths.

 

[dougelam]

A "quick and dirty" test is turning your key ON and see if the rear alternator bearing has become highly magnetized. If so your voltage regulator is working because the rotor has become energized but it doesn't tell you if your voltage regulator is able to correctly adjust the output voltage. When working correctly it should limit the output voltage from 13.8 to 14.2 volts but that can vary a few tenths.

How would you know this using an amp meter?

I have always preferred ammeters because they tell me how many amps my alternator is putting out.

Sent from my SM-N920P using Tapatalk

 

[kpic]

How would got know this using an amp meter?

Good question.

I can't wait to hear TBTR's answer.