How to test a voltage regulator on any car with an alternator. You have a voltage regulator and this voltage regulator is responsible for keeping the voltage on the vehicle from exceeding a limit.
Usually this limit is 13.8 to 14.2 volts, which is enough voltage to allow for proper battery charging, but not enough to burn out light bulbs or damage delicate computer circuits.
The best way to test a voltage regulator is with a multimeter, and what you do is you put your multimeter clamps directly on the battery terminals. Positive read to positive and black to negative. And you said it to voltage, and with the car off, you should have a little over 12 volts. That’s that’s a healthy battery. And when the ones you’re hooked up, you want to start the vehicle.
And what you’ll see is that at idiable, the voltage will increase. This means that the alternator is charging the battery. We’re making about 13.8,13.9 volts. And so at this point, what you want to do is you want to slowly start increasing the speed of the engine.
And once you hit between 1500 and 2000 APM, the voltage should reach a point where it no longer increases.
And what we’re noticing is that it’s maxing out right around 13.9,8,9,7or so, which is well within that 13.8 to 14.2.
So this voltage regulator seems to be working fine. If the voltage keeps climbing with the RPA ends up in the 15+ volt range, then the voltage regulator is not doing its job and it needs to be replaced. If the voltage is too low, then the alternator is not charging properly and it needs to be rebuilt or replaced.
And lastly, if the voltage with the vehicle off is below 12 volts, then the battery is most likely in need of being replaced.
Some Frequently Asked Questions
- Dimming or Pulsing Lights. A damaged or failed voltage regulator can rapidly diminish the alternator’s ability to cycle power from the battery.
- Dead Battery. A burned-out voltage regulator will diminish the vehicle battery’s ability to charge or stop it altogether.
- Unpredictable Engine Performance.
*The information above does not constitute legal advice or opinion, nor is it a substitute for the professional judgment of a qualified attorney.