Harley Davidson Voltage Regulator Symptoms & How to Fix It

Let’s be up front, Harley Davidson bikes aren’t known to be the most reliable or durable among the riding community. Despite that, there are enough Harley riders that most problems are well-documented with easy enough solutions.

One of the main issues that plagues Harley owners have to do with the voltage regulator. If you know the symptoms, you’ll be able to manage your voltage regulator problems before it becomes too big of an issue.

In this post, let’s take a look at some of the Harley-Davidson voltage regulator symptoms you should be aware of as a Harley owner. We’ll also dive into the solutions for fixing the voltage regulator. Let’s jump right into it!

harley cruiser

What is the Harley Davidson Voltage Regulator?

The Harley-Davidson voltage regulator is an electrical component that controls the amount of voltage going into the instrument gauges, speedometer, and gauge cluster. It’s required by the motorcycle electronic system to display the engine speed and other important vitals.

Problems with the Harley voltage regulator will eventually lead to issues with information being properly displayed. This includes the state of your motorcycle’s engine, it’s running condition, speed, and everything else that’s revealed on the instrument cluster.

It also happens to be one of the most common causes of electrical problems with Harley Davidson bikes. Along with the battery, it’s the voltage regulator that many riders will be familiar with when it comes to diagnosing electrical issues.

In order to fix the voltage regulator, you need to be aware of the symptoms. Let’s take a look at those in the next section.

Harley Davidson Voltage Regulator Symptoms

black harley davidson cruiser

There are a few symptoms you may start noticing that reveal an issue with the voltage regulator. Keep this in mind if you’re having trouble with your Harley before worrying that it’s more serious of a problem.

Flickering Gauges

One of the first symptoms of a failing or faulty voltage regulator are dim or flickering gauges. Since it’s the regulator that supplies power to the gauges, the gauges will start to dim and flicker if there’s an issue with the power supply.

It can be difficult to notice this issue during the day, especially if you’re riding in bright conditions. However, if you’re riding at night or in low light conditions, you’ll definitely see an issue with the gauges and turning signals.

If you notice your gauges flickering, check the turning signals as well. Park the bike, turn on the signal, and check to see if the signal is flickering.

Instrument Cluster Fails to Turn On

Another telltale sign that you’re dealing with a faulty Harley voltage regulator is that the instrument cluster fails to turn on. You should notice this after putting in the key and turning it to the on position.

With a faulty regulator, none of the normal lights will illuminate. What’s happening is that there is no power getting to the instrument cluster, which is why it’s disabled.

While you’ll probably be able to turn on the bike and go for a ride, you’ll be missing out on the instrument cluster information. After checking that the battery isn’t faulty, if there’s still an issue here it’s probably with the voltage regulator.

Cluster Displays Erratic or Inaccurate Reading

One more obvious Harley voltage regulator symptoms is that the cluster displays erratic or inaccurate readings. You might see the speedometer jumping up and down or various gauge lights flashing on and off.

Seeing these symptoms on your bike immediately reveals that there is an issue with the voltage regulator. It’s not safe or recommended to ride if you’re not able to determine your speed or become alterted of any other warning lights.

Again, while you could keep riding without a properly functioning instrument cluster, this is not recommended or a good idea. You won’t be able to determine your speed or know if there are any other issues with your bike.

Testing the Voltage Regulator

If you noticed your Harley losing voltage or suffering from voltage regulator symptoms, it’s possible to test the regulator for bleed. Voltage is only allowed to travel in one direction, from the stator to the battery, when the regulator is working properly.

If the regulator is leaking voltage, the battery will also be leaking voltage. This is a condition that’s easy to test.

Using a multimeter, clip the test light on to the negative terminal of your battery. Next, unplug the regulator to get an accurate voltage reading.

Using the test light, touch each of the regulator terminals one at a time. If the test light illuminates, the regulator is faulty and needs to be replaced.

Battery voltage isn’t supposed to be present on this side of the regulator. Should you notice any issues, test the charging system as well.

How to Fix the Voltage Regulator

Most riders with this issue will want to bring in their Harley-Davidson to an authorized dealer or prefered local mechanic. This is the easiest way for the voltage regulator to get fixed.

While it’s possible to do it on your own, it’s more of an advanced motorcycle repair. Those of you with the skills and confidence will want to refer to YouTube for some helpful tutorials.


clean harley davidson

Not only is it disappointing and frustrating, it’s also unsafe to have to ride your motorcycle with a faulty voltage regulator. If your bike is suffering from electrical issues, start by checking for the regulator symptoms that we covered in this post.

It’s a good idea to always follow regular preventive maintenance when it comes to properly maintaining your motorcycle. This will allow you to discover issues and symptoms before they become serious problems.

Regardless of the Harley-Davidson you’re riding, all of them come with voltage regulators. In order to know whether or not the regulator needs to be replaced, a proper diagnosis needs to be carried out.

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