What Are The Symptoms Of A Bad Voltage Regulator On A Harley Davidson?

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If you see some weird things with your Harley Davidson, it can be a good idea to check the voltage regulator. A voltage regulator is crucial in controlling how much electricity flows in and out of your bike.

Your bike needs at least 13 volts for its parts to function properly. When the level drops below this threshold, it will either drain or completely shut down the battery power supply, so if you notice problems like dimmed lights or poor starts, you might want to give it a look just in case.

Moreover, if everything looks okay with the voltage regulator when you test them out by measuring their resistance, other possible causes need to be investigated. One of these is a loose or corroded connection. You can do this by using an ohmmeter to measure the resistance between two terminals on your battery and ensure they’re not touching anything else besides where you test them for continuity.

In this article, we will explore the symptoms of a bad voltage regulator on a Harley Davidson. What does it mean when you hear “voltage regulator”, and how can you tell if your bike needs one? What are some common causes for problems with voltage regulators? What is the cost to replace or repair a faulty voltage regulator?

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What is a Harley Davidson voltage regulator?

A voltage regulator is a device that regulates the output of an electrical machine. It usually steps down the input to produce an output that will operate at some fixed or variable lower level. Voltage regulators are used with electric power generation and distribution systems, industrial machinery, vehicles (such as cars), telecommunications equipment, household appliances, aeroplanes, and spacecraft.

What does the voltage regulator do on a Harley Davidson?

The voltage regulator is a key component of Harley Davidson motorcycles because it regulates the power flow to each gauge on your bike. This device ensures that you have a smooth ride every time you fire up your hog, without any sudden spikes in power or fluctuations in speed.

Regulating the flow of power coming from your battery ensures that you receive a steady stream of voltage, mostly unchanged.

A Harley Davidson’s voltage regulator acts as a filter for power coming from your battery which means that it removes any spikes in pressure or fluctuations in speed.

For example, if you were to stop at a light and turn off your bike, the engine would die, but the headlights would stay on because the regulator allows for this fluctuation in voltage to happen without damaging other parts on your bike.

It also ensures that no matter how long you’ve been riding continuously—whether it is 30 minutes or six hours—the regulated flow of electricity ensures there are no sudden drops in power while still maintaining enough force to keep everything up and running.

Sign of a Bad Voltage Regulator on a Harley Davidson

I see you’ve been looking for some answer to the question “What are the Symptoms of a Bad Voltage Regulator on a Harley Davidson?” Well, let me tell you about the symptoms first. The voltage regulator is an electrical device that regulates voltage, and it’s one of those things that can’t break at a good time. If your bike has any of these signs, then you might have to replace that thing:

  1. Power Failure
  2. Headlights burn out over time
  3. Gas fusing out of battery
  4. Malfunction in engine light
  5. Gauge Flickering
  6. Error reading the cluster
  7. Faulty voltmeter reading

01. Power Failure

Power Failure One of the first signs that your Harley Voltage Regulator is bad is if the cluster can no longer turn on. The cluster is an important part of your Harley Voltage Regulation. If you notice that power isn’t working to the cluster, it means that you need to take your bike to someone who knows how to fix it. Sometimes, even though this happens, people’s bikes start, but they might have a speedometer problem during their trip.

02. Headlights burn out over time

Many things can go wrong with a bike. One of the most common is having a headlamp or tail lamp not work. This can happen because of too much voltage, and this might happen because the bike has an old battery or a bad voltage regulator.

03. Gas fusing out of battery

Batteries release flammable gases if the voltage regulator is faulty. When a battery is overcharged, it releases hydrogen and oxygen. If your Harley-Davidson has any of these symptoms, you need to have your regulator fixed by an expert mechanic.

04. Malfunction in engine light

Another thing that might happen is the malfunctioning of the indicator lights on your dashboard. If they aren’t working, it can be an issue with either you have a faulty voltage regulator or need to change your battery as well! Power Failure

It’s really important to make sure that you don’t stop using your motorcycle at a random place and try starting it again. This might damage the entire electrical system of your bike if it doesn’t start up on the first shot!

05. Gauge Flickering

If they aren’t working, then there is probably something wrong with the voltage regulator of your bike. The needle on the voltmeter is also a sign that something isn’t right with this part!

06. Error reading the cluster

If you start seeing some random numbers and Xs appearing in place of all those dials, then it’s time to get it checked by an auto mechanic, or else there’s a possibility that this might cause further damage to your bike.

07. Faulty voltmeter reading

If the voltage readings on your meter are wrong, this might be because of something causing a lot of heat. If you have a good engine and the reading is high or low when it should be normal, the regulator might not work right.

Harley Davidson voltage regulator problems

Harley Davidson voltage regulator problems are easy to come by, but Harley Davidson’s tend towards being more expensive than many other motorcycles. Harley-Davidsons are beautiful bikes that can be very hard on the wallet. Here I will discuss Harley Davidson voltage regulator problems and how you can avoid them.

  • Gases Are Emerging From the Battery

As I’ve said earlier, you need to make sure that your battery is not overcharged. If your battery gets overcharged too often, it will become like a balloon. The liquid inside the cell will turn into hydrogen and oxygen. These are both very flammable gases, so stay away from them if you have something that can catch on fire.

  • A deceptive voltmeter

If you have a voltmeter on your dashboard, it will show unusual readings. Sometimes the reading will be too high, and sometimes it will be too low. When the circuits get damaged due to extreme heat, the voltage will be much less than required for ideal working.

The voltmeter is called a deceptive voltmeter because it doesn’t show the correct reading when there is no current in an electric circuit or when there is too high of a flow of current through the meter itself. The only accurate way to measure voltage drop in an electric circuit would be to let the current slowly pass through, but it would take hours to measure even a few volts.

  • Burn-out Lamps

Some cars have a problem when they get too much voltage. The battery, headlamps, and tail lamps can burn out because the car cannot handle the heavy voltage. When this happens, it is time for a new battery or lamp!

Cars can keep on running with a defective voltage regulator. You may even be able to drive at very high speeds, and your car will not overheat too much. The whole system works in harmony, though if everything is working together, it cannot handle high levels of heat and pressure.

  • Flickering Gauges

Another problem when the light flickered is that it can be hard to read when you are out riding at night.

There are many reasons why your Harley Davidson’s voltage regulator keeps going bad on you. Sometimes, the light will flicker or get dark. This is because there is something wrong with the power regulator. Another problem could be that it’s hard to read out what the gauge says when riding at night.

  • The instrument panel in the car is not working

The car’s instrument panel is not working. This might be because the bike has a bad regulator, which causes problems with the instrument cluster in the car. The bike can still start, but there will be no information on it. It is very unsafe to ride your bike if you cannot tell how fast you are going.

Another sign of a bad regulator is that it causes the horn to blow, headlights to turn on and off, wipers to work at full speed, the stereo may come on or go off by itself. There are many problems associated with a bad voltage regulator in your Harley Davidson motorcycle.

  • Inaccurate Readings

Inaccurate readings can happen for a few reasons. One is that the voltage regulator has been damaged and is not working well. The numbers and needles change rapidly, which can make it hard to understand what they are measuring. The numbers may also be off from the actual voltage, which can cause problems if it is too low or high.

Incorrect parts being used may have been installed in place of the correct ones. These incorrect parts will not work and could damage your Harley Davidson, so always use a professional to determine what part needs to be replaced.

What Could Be the Cause of This Issue?

At first, let’s understand your motorbike’s voltage regulator. It has 2 parts. There is a part for converting AC power to DC power and making sure you don’t overload the battery. Your Harley’s voltage regulator is not working if one of these parts is not working well or something else in the bike makes it not work right.

The regulator can fail due to many different reasons. It simply not working right is one that happens often. There are many more complicated causes, but they all end up in the same place: something isn’t letting it work properly, and you need to care for your Harley’s voltage regulator.

Let’s dig into some of the most common reasons why your bike’s voltage regulator is not working right.

  1. Damaged Internal Components
  2. Excessive Vibration
  3. Misfiring, Backfiring, and Shots

01. Damaged Internal Components

The voltage regulator may be worn out due to age. The older ones don’t function as well as the newer versions. As the regulator is utilized more, the chance of encountering this problem increases over time.

Apart from getting older, heat can also cause problems with your bike. If your bike stays hot for a long time, the heat can damage other things on your bike, like the regulator. The heat can damage the regulator so much that it won’t work correctly anymore.

02. Excessive Vibration

If your bike vibrates too much, then the regulator can get damaged. If it is not secure where vibrations won’t reach it, you will be at risk of losing voltage regulators over time. Maintaining proper security and stability for all parts of your Harley Davidson motorcycle is very important if you want to avoid unnecessary problems.

03. Misfiring, Backfiring, and Shots

Sometimes, the engine can have problems. It will misfire or backfire, which affects the voltage regulator. When this happens, it is hard for the charger to control how much energy is going into your battery. This means that sometimes too much energy goes in and wears out or damages other electronic parts on your bike.

How to Repair a Voltage Regulator Rectifier?

If you find getting an OEM voltage regulator very expensive, you can consider repairing the thing by yourself. Even if the regulator rectifier is very weak or damaged, you can still repair them without spending much money and effort.

Although, you can fix the regulator by yourself. This will help make sure your bike works right.

There is no need for any special knowledge or skills. Anyone can learn how to do this.

To complete your journey, you’ll need to have…

  • Rectifier shim
  • Microclyder ring

At first, you need to take off the back of the regulator and take out all the electronics. There will be two parts glued together. You need to separate them apart carefully.

Then there will be a shim that is, in most cases, what needs to be replaced, but it has been taken off from the old one before, so you have to do that before it can break into pieces!

You’ll find a ring beneath the shim- this too must be changed because it wears out due to high voltage. Remove this ring and put a new one on in the same place as before, so electrons are gapped correctly again- use copper for best results.

Now put a new shim on top of this ring with glue and make sure that the covers are secure before putting it back on your bike. Your Harley will not have issues anymore.


If your Harley Davidson’s battery is not charging, you may have a bad voltage regulator. This component regulates the power coming from the alternator to charge the bike’s 12-volt battery. The regulator also prevents overcharging of the battery if it exceeds 14 volts. A faulty voltage regulator will result in an undercharged or dead battery and can lead to electrical failures on other components like headlights, turn signals, radios, etc., so get this checked out right away.


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