What causes a voltage regulator to go bad

Every car has a battery to crank the engine, and power the fuel pump and ignition at startup, but then the alternator starts spinning and providing the power. Because of this, you can often jump start a car with a failing battery, then drive it to the auto parts store to get a new one. There are only a few ways an alternator can go bad, but they tend to happen suddenly without a lot of warning.

Here are the common symptoms:.

Bike problems solved! Regulator/Rectifier

Like all rotating machines, the bearings in an alternator have a finite life and will eventually go bad. You can minimize the chances of this happening prematurely by keeping the drive belt and tensioner in good shape.

If your car has a spring-loaded tensioner, you should at least inspect it at 50, miles when you change the belt. If you have an older car with a manual tensioner, be sure to tighten it to the specification found in your Haynes Manual. If you notice an acidic smell or your battery is leaking fluid, it may be because the alternator is overcharging.

You can easily check by measuring the voltage at the battery with the car running, which should not go above 15 volts even with the engine revving. First, check that all the wires to the alternator and regulator are connected properly and not broken. If your car uses a voltage regulator, either separate or built into the alternator, it is inexpensive and easy to change.

If you have a car where the voltage is regulated by the ECU, you may need to talk to an expert technician. But, if the low output is combined with squealing noises, it may just be a case of a slipping serpentine belt. If the belt is good, low output can be caused by the insulation breaking down on the internal alternator windings, or it may just be worn brushes; either way, the unit needs to come off and come apart.

Finally, if there is no charge at all, there are several possibilities. It is possible that the drive belt has broken or come off the pulley, or the tensioner went bad completely. Alternators put out alternating current, and the battery needs direct current to charge, so there is a voltage rectifier that converts it, and it can suddenly go bad, too.

What Can Cause a Regulator Rectifier to Go Bad?

A faulty voltage regulator can also stop an alternator from charging at all. Otherwise, a no charge condition can mean an internal break in the windings, bad brushes, or burned out slip rings. If all the external wiring seems good, it is likely an issue inside the alternator. The single best thing you can do to keep your alternator working well is to keep it clean and dry. Dust and dirt can get into the alternator, and over time cause shorts or wear on the brushes.

Heat and oil can also shorten the life of an alternator, so fix under hood leaks as soon as possible. Go to front page. Search results Search Haynes. Year Year Make Make. Model Model. Here are the common symptoms: Undercharging - This is the most common problem, and can often be caught in the early stages.

If you notice your headlights get dim with the engine at idle and get bright when you rev it, chances are your alternator is not putting out enough power. An overcharging alternator can kill a battery and boil the fluid out of it.

No Charge at All - This can appear just like an undercharge condition, but revving the motor does nothing. Get home or to a service station quick, as a modern car will only run a short time before the battery is dead. Mechanical Issues - This category of failure often just involves the bearings wearing out and squealing, or in extreme cases, seizing up.The voltage regulator in your vehicle is in charge of keeping the right amount of electrical power flowing consistently to certain parts of your car.

what causes a voltage regulator to go bad

This means if the voltage regulator is broken, the components in your electrical system might only work erratically or not at all. This is because when this part burns out, the battery will no longer charge, meaning it will eventually die.

what causes a voltage regulator to go bad

Another way you can tell the voltage regulator is bad is when the car lights keep dimming or flickering. This issue can extend to your headlights, dashboard lights and even your sound system. It might also have trouble accelerating as you drive.

If, after testing the voltage regulatoryou notice the numbers on the gauge seem to be changing erratically, you probably need a replacement for this part.

It could be another problem that presents similar symptoms, so look into other possibilities—such as signs your alternator is bad —as well if you want to get to the bottom of the issue.

Keep checking your regulator on regular basis. Also do replace the regulator in car and other vehicles if you are going for long trip. I have a Pontiac Montana…. I had the alternator and battery replaced both new.

My vehicle is experiencing erratic behavior…while It is operating on the road, the entire lights go out, speedometer goes to zero for a split second……. My question: What brand name alternators should I consider or not consider as a replacement??? Thank you for your help here it seems to be helping but I have a question if you have a bad voltage regulator and disconnect the battery terminal will the engine die or should will it keep running Mahalo and thank you for your time.

Skip to Main Content. Search for: Search Now. Login My Cart Toggle Dropdown. Back to Blog. Bad Voltage Regulator Symptoms The voltage regulator in your vehicle is in charge of keeping the right amount of electrical power flowing consistently to certain parts of your car.

Bad Voltage Regulator Symptom 2: Your Lights Are Dim Another way you can tell the voltage regulator is bad is when the car lights keep dimming or flickering.

Leave a Reply Cancel reply.It is a fact of life: parts will eventually go bad. One motorcycle part, the regulator rectifier, generally gives some additional signals that it is not operating correctly.

Also, chances are that you have had some start-up or voltage issues. Confirming that it is indeed the regulator rectifier that requires observing and checking certain symptoms. Modern motorcycles have electrical charging circuitry for the battery, of which the regulator rectifier is a standard part. The name of the part is actually indicative of its function as it rectifies and regulates voltage.

what causes a voltage regulator to go bad

AC voltage is generated in the alternator's stator coil. For the most part, motorcycles are on a three-phase system for efficiency purposes, where three wires connect the stator and regulator rectifier.

Even so, there are some single-phase systems available as these are cheaper to manufacture, but the system uses two wires instead of three. The regulator rectifier first converts the AC power into a surge of DC power, then normalizes the DC power, ensuring that the power does not exceed approximately The DC voltage is then routed to the battery.

There are different reasons why the regulator rectifier fails. One of the top causes is heat. Some motorcycles are known to have the part located near the radiator or other locations that are either close to heat producers or restrict air flow. Depending on the location of the regulator rectifier, the part can easily overheat.

Other causes for a dead regulator rectifier center on the battery. Ground connections are important for good voltage, and if there is faulty voltage, the regulator rectifier can run hot.

Bad Voltage Regulator Symptoms

Bad grounding, corroded battery connection and poor or loose battery connections will cause faulty voltage. There are generally two ways for the regulator rectifier to fail. The first deals with diode burnout, resulting in battery drain. It is easy to assume that the issue is a bad battery because of symptoms such as dimming headlights, irregular meter readings and poor starts.

Checking the voltage with a voltmeter versus relying on symptoms alone will prove highly beneficial. If the voltage drops below approximately 13 volts, the motorcycle will begin to drain the battery and eventually the engine will stop. Check for bad connections and corrosion; these also can cause voltage issues. The other failure type is shunt regulator burnout.The instrument cluster voltage regulator is an electronic component that is found on certain cars and trucks.

Usually a faulty instrument voltage regulator will produce a few symptoms that can alert the driver of a potential issue. One of the first symptoms of an issue with the voltage regulator is dim or flickering gauges. The voltage regulator provides power to the gauges, and can cause it shine dimly or flicker if it has an issue. In certain cases the gauges and indicators may still function, however it may be difficult to read the instrument cluster, especially while driving in low light or night time situations.

Another symptom of an issue with the voltage regulator is inaccurate or erratic readings from the voltage regulator. If the voltage regulator has an issue it can cause the gauge to display inaccurate or erratic readings. The numbers on the displays, or the needles, may change rapidly or cut on and off erratically.

If the instrument voltage regulator fails completely, power to the cluster will be disabled and it will cease to function. In some instances the vehicle may start up and drive, however the driver will be left without any information from the cluster in case a problem occurs, and without a functioning speedometerwhich apart from being unsafe, is also illegal in many jurisdictions. Voltage regulators are not found on all vehicles, however they serve an important function for the ones they are found on.

It is important to note that similar symptoms can also be produced by electrical issues, so a proper diagnosis from a professional technician, such as one from YourMechanic, is recommended in order to determine if the regulator should be replaced. The most popular service booked by readers of this article is Vehicle Body Electrical and Lighting Inspection. Our certified mobile mechanics perform over services, including diagnostics, brakes, oil changes, scheduled mileage maintenances, and will come to you with all necessary parts and tools.

Our certified mobile mechanics make house calls in over 2, U. Fast, free online quotes for your car repair. Service Location. Dim or flickering gauges One of the first symptoms of an issue with the voltage regulator is dim or flickering gauges. Inaccurate or erratic readings Another symptom of an issue with the voltage regulator is inaccurate or erratic readings from the voltage regulator.

Instrument Panel. Home Articles. The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details.A voltage regulator maintains an even flow of electrical power to an automobile's electrical systems, including the headlights, dashboard components and the stereo.

When the parts fail or begin to show symptoms of failing, it can have far-reaching implications to the viability of the automobile. You may notice dimming headlights or unpredictable engine function and even a dead battery. As soon as you notice the symptoms, take the vehicle for an in-depth inspection before the problem leaves you on the side of the road.

A damaged or failed voltage regulator can rapidly diminish the alternator's ability to cycle power from the battery. This may cause the vehicle to experience dimming or pulsating external systems, such as headlights and dashboard elements. In addition, the "check engine" or "battery" light may appear on the dashboard when the initial failure is detected by the vehicle's on-board computer.

A burned-out voltage regulator will diminish the vehicle battery's ability to charge or stop it altogether. You will quickly find the vehicle unable to start due to a dead battery. If the battery is recharged, the vehicle will start, although the faulty voltage regulator will only cause the battery to lose power rapidly. In this case, the vehicle should immediately be taken to a mechanic once the battery has been recharged or the car has been jump-started to have the voltage regulator replaced.

Some aftermarket voltage regulators have experienced problems working in factory-built systems. Engine stalling, sputtering and intermittent acceleration will occur when the vehicle's voltage regulator is unable to handle the power put out by the vehicle's stock and faster-moving alternator.

This causes the regulator to burn out quickly because it was overworked. Have either a certified mechanic or someone with extensive knowledge of the vehicle being modified look at the aftermarket parts.

This article was written by the It Still Works team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Works, contact us.

Unpredictable Engine Performance Some aftermarket voltage regulators have experienced problems working in factory-built systems. About the Author This article was written by the It Still Works team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information.The energy that the car needs is supplied by the fuel and by the battery.

Looking for a good online repair manual? Click Here for the 5 best options. You need plenty of power to keep the engine running.

Some of the electrical systems in your car would fry if exposed to raw current, which is where the alternator voltage regulator comes into play. Related: Causes of an Alternator Not Charging. There are a few different types of regulators on the market. They all have the same function, though.

what causes a voltage regulator to go bad

The battery is a reservoir to store energy. It is kept on standby for functions like starting the car and providing power when the power supply is low. Related: Symptoms of a Bad Car Battery. The alternator is the component that produces that power.

The voltage regulator ensures that the maximum amount of voltage in the circuit is kept constant. It can, therefore, prod the alternator to up production or prompt it to reduce energy production. The idea is to create a steady stream of current that can power the vehicle consistently.

Symptoms of a Bad Voltage Regulator

The good news is that voltage regulator failure is one of those problems that develop over time. There are various troubleshooting techniques that will help you diagnose this issue. A typical car battery should put out about Once the car is running, the voltage should measure around 2 volts higher in most vehicles. Too high of a voltage can actually cause damage to various electrical components.

Most commonly, the bulbs in your headlights or taillights will prematurely burn out. If you have a bad regulator, it may cause many components such as the fuel pump, ignition system, or other parts which require a minimum amount of voltage to not function correctly. You may experience the engine sputtering, a rough idle, or simply a lack of acceleration when you need it.

Like other electrical components, the instrument cluster requires a certain amount of voltage to display all the information you need while driving.

Symptoms of a Bad or Failing Instrument Voltage Regulator

A bad voltage regulator may cause it to simply not work or behave erratically. It again points to a current that is not being adequately controlled. This symptom exists for battery related issues but can also mean the voltage regulator is to blame. One of the systems that can be adversely affected by too much or too little voltage is your headlights. The high-beam headlamps particularly require a fair amount of power to operate.

Corrosion spreading on the terminals and top of the battery can be a sign of a failing voltage regulator among other things. It might be due to a host of other causes, including forgetting to switch off your lights, a problem with the alternator, or simply an old battery that needs to be replaced. But it could also be because of poorly managed current due to a bad voltage regulator. For replacement parts, we recommend: PartsGeek.Forums New posts Search forums.

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Thread starter chuglife Start date Jan 12, Watchers 4. Joined Aug 15, Messages Location Calgary. Just go to Napa and get a new one. I lucked out as there is one Napa in Atlanta that stocks them, I've had to buy two. I did the upgrade, cost a lot more than the new factory replacement, did not notice any improvement.

When the upgrade died, I replaced it with stock. If you do decide to do the upgrade, I can send you the harness I made for mine.