Feedback +

If you would like a response, please supply your email

Toggle Nav
Menu
Account

How To Test Your Voltage Regulator

 
 Battery charging issue seems to be a common problem with our vintage British cars. Here the Moss Motors Tech specialist walk you through checking your voltage regulator to see if it is functioning properly. Does the problem lie in the generator, wiring or voltage regulator? This video will help you eliminate one of the culprits. See our How to Test your Generator to get the rest of the story.


We’ve already tested our generator and we know it’s good, but we’re still not charging. In a case like that, either the voltage regulator, or the wires that go to it, are suspect.

The voltage regulator sends power out through the field terminal that goes to the generator and that’s how the generator comes to life. So for test purposes, what you want to do, is with the wires still in place on your voltage regulator, get a jumper lead connected to a power source. Wiggle that on in until making contact with the field terminal. Now we’re sending full field current to the generator. When we do that, we’re doing the voltage regulator’s job. When we do the voltage regulator’s job, if the generator comes to life, the voltage regulator is probably our problem. However, with the wires in place, if we put full current right here with that wire that goes from the field to the generator and she still won’t come to life, chances are strong the problem is in the wiring between here and the generator.