What does it mean when your alternator stops charging the battery?

Indicator Light On. Usually, the first sign that your charging system is in trouble is a “battery,” “ALT,” or “CHARGE” warning light illuminating on your instrument panel while driving. It means that for some reason, the alternator has stopped charging the battery and your car is running on battery power.

Why does my alternator not charge on tickover?

On checking the battery voltage was low – 11.8V engine running. Battery was replaced about 1 month ago.After much investigation discovered that the alternator does not ‘kick in’ until I rev the engine to approx. 3000rpm – it then charges away happly for the rest of the journey (at around 14.5V) even on tickover. Has anyone seen this problem before?

How can I tell if I have an alternator problem?

To differentiate an alternator problem from the battery, you will need to use a voltmeter to check for voltage. First, turn off the engine and check the battery voltage. A fully charged battery should have a reading of 12.65 volts. Next, turn on the engine and recheck the voltage. You should have a reading of 13.5 to 14.5 volts.

Can a loose alternator cause a car to not start?

Alternator and Starter Diagnosis. A loose starter may crank an engine slowly, noisily or not at all. Loose bolts will make for a weak ground connection. The starter may also flop around, slip, chatter or fail to engage depending on how loose it is. Sometimes the engine won’t crank even though the starter will spin.

Can a bad alternator cause a car to start?

A properly-functioning alternator will show above 14V while running. They could be damaged, causing symptoms that look like a bad alternator. It is a very common and very well-documented issue in early 997’s. The alternator to starter motor cable isn’t quite heavy-duty enough and can corrode internally or even melt.

Why does my car not start when I change the battery?

Look for dimmer headlights or trouble cranking the engine. Additionally, if the serpentine belt starts to slip or is worn, it won’t be able to power the alternator, thereby leaving you with a dead battery. Many people figure out that the alternator is bad after replacing a battery and having the same issues.

How can I tell if my alternator is working or not?

If the battery is working properly and nothing is wrong with it, then it’s the alternator that will more likely cause a problem. A simple test to check the working of the alternator is by running your car; and then unplugging the positive connection of the battery.

What happens when the alternator of a car is dead?

The alternator and the car’s battery work hand in hand. A good battery should give you service for the next five years before its lifespan ends. If your battery is dead, then it will not give power to the car’s alternator. The alternator normally lasts longer than the battery.

Is it time to replace your alternator or battery?

If so, it’s time to replace it. Some may recommend running the engine with the negative battery cable disconnected to test the alternator. However, this is not a good idea because it could damage the electrical system of your vehicle and cause greater problems. Fixing your battery or alternator can be an expensive repair.

What happens if the alternator is not working?

The alternator charges your battery while you drive. If your alternator fails, your battery doesn’t charge and eventually dies. How long will a car run without an alternator? If your alternator isn’t working, your car can barely do more than start before you begin losing power.

How does an alternator and battery work together?

Anything less than that and your car isn’t even able to start. Both of these car parts control your electrical system. However, your alternator charges your battery while your battery supplies power to your car. The failures of a battery are sudden, while failures of a failing alternator are slow.

When to know if your alternator or battery is dead?

If the engine starts but dies immediately, your alternator probably isn’t keeping your battery charged. If a jump starts and keeps your car running, but the car can’t start again off of its own power, a dead battery is likely your answer.

How long does an alternator last in a car?

On average, car batteries last between 2 and 5 years. Eventually, the level of battery charge diminishes to the point where, no matter how much power the alternator gives to it, the battery can’t hold enough power to start the car.

What causes the battery light to go out?

Click to expand… Many charging systems put the alternator energizer wire through the light bulb. When the alternator starts charging positive voltage is equal on both sides of the bulb filament and the light goes out.

Why does my alternator get higher than base voltage?

You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

What should voltage be for car battery light?

It’s relatively easy to check the function of the alternator with a multimeter. The voltage should be between 13.6 volts and 14.6 volts. If the voltage is less than 12 volts, the battery light is triggered and you’ll likely need to replace the alternator.

What’s the battery voltage on an old alternator?

The old alternator tested good at Autozone. The battery has 11.8 volts now. Turning on the ignition drops that to 11.6. Starting the car drops it to 11.4. The alternator to body voltage with the engine running is 11.4 volts.

What happens if you have a bad alternator in your car?

But if you have a bad alternator, then it won’t be able to keep the battery charged. This will cause the car battery light to illuminate once there is an inconsistency in the charge. Once the alternator completely dies, the power that is left in the battery will be exhausted in a matter of minutes.

When does the alternator turn on the idiot light?

When the engine starts and gets up to a high enough rpm for the alternator to start putting out voltage, there is a diode inside that takes some of the output voltage and featured back to the terminal that goes to the idiot light.

What are the symptoms of a bad alternator?

BAD ALTERNATOR SYMPTOMS: 1 Dim lights. The failing alternator symptom most drivers recognize is dim or flickering lights. 2 Service engine light. Another obvious sign is the one your vehicle tries to tell you. 3 Odd noises. 4 Electrical issues. 5 Engine stalling. 6 Dead battery. …

Why does my alternator light up when I change the light bulbs?

Accompanied by flickering headlights is a constant and abnormal burning out of headlight bulbs. If you have to change the light bulbs in short intervals (like once a month), grab a multimeter and check the alternator voltage output (if it’s too high). Changing the headlights bulbs is usually an easy job.

Can a bad alternator keep a car going indefinitely?

An alternator can help replenish the battery in your car, but it can’t keep it going indefinitely. This means it’s important to distinguish between a weak battery and a bad alternator.

Why does my alternator light get brighter when I Rev the engine?

This voltage drop causes the light to light, and also results in the battery charging poorly if at all. Usually when this is the case, the light will be very dim at hiatal and will get brighter as you rev the engine.

How to know if your alternator is working properly?

1 Check the drive belt or serpentine belt. Look for signs of wear or damage like cuts, shiny spots or missing chunks under the belt. 2 Also, check the belt tensioner for proper operation and damage. It should rotate freely. 3 Make sure the alternator is properly mounted. 4 Check the alternator for noises. …

Is it safe to turn on heated windshield alternator?

But don’t turn on the heated windshield if your vehicle has one; alternator voltage may increase to over 100V and this can be unsafe. Take a voltage reading across the battery posts. Your reading should be at least 0.5 volts above base voltage for your system to keep up with electrical system demands.

What happens when the diodes in an alternator go bad?

Alternators use diodes to rectify alternating current produced by the alternator into direct current. When one or more diodes go bad, the alternator can cause all kinds of problems. AC voltage leak can cause your lights to dim and drain power from your battery, for example.

What causes a radiator alternator to stop working?

A closer observation of the radiator will reveal a system of pulleys or belts that work to convert mechanical energy into electrical energy. The alternator will stop working the moment your belt wears out and breaks or the pulley becomes damaged. These items are easy to replace. 3. Faulty fuse Fuses blow up due to a power surge or they wear out.

Do you have to loosen the alternator before replacing it?

Loosen and remove the alternator. If you have a V-belt, the alternator must first be loosened before the V belt can be removed as the alternator provides belt tension. Install the new alternator, making sure that it fits properly and aligns with the existing bolt holes, by reversing the steps in the disassembly procedure.

How does the alternator work in a car?

The alternator is a key component in running the electrical systems in your car. The alternator takes the energy from the crankshaft and turns it into the electricity that is stored in the battery of your car. When your car is running the alternator helps to power the different electrical systems in your car and keep your battery charged.

Is the brake and Battery Light a problem?

The car ran fine for a while (the brake and battery light went off) so i thought it was fine. Low and behold, it died again in the middle of nowhere Now i’m screwed because i don’t know what it can be. We tested the battery with the car off (12 volts) and tested it with the car on (dropped to 11.8 volts.)

Is the alternator on my Ka car working?

We tested the battery with the car off (12 volts) and tested it with the car on (dropped to 11.8 volts.) Then, with all the lights on, it dropped to 11.0 volts. I know it seems like the alternator isn’t working, but i’m sure that alternator was working on my KA.

What happens to an alternator if the battery is shot?

If the battery is shot it’s a risk, but of the battery is good and the lights were left on, it should recharge without incident to the alternator. I suspect that while the initial load on the alternator of any drained battery is high, a good battery will charge and the load to the alternator will go rapidly enough that there should be no damage.

How to tell the difference between bad battery and bad alternator?

Bad battery or bad alternator symptoms, how to tell the difference (brief) not charging. – VOTD – YouTube Bad battery or bad alternator symptoms, how to tell the difference (brief) not charging. – VOTD If playback doesn’t begin shortly, try restarting your device.

What happens if an alternator is charged at full charge?

An alternator that continues to run at full charge, trying to charge a defective battery, will fail. It can overheat and take out bearings, diodes and regulators. Get your facts straight before weighing in on something you know nothing about. Alternators can and will fail if they continue to run at full charge.

Can you drive a car with a faulty alternator?

Faulty diodes can easily be replaced, but you will need to dismantle the alternator. It is impossible to drive the car with a faulty alternator. While it is the work of the battery to power the electrical components in the car, it cannot do this alone.

Can a broken belt cause an alternator to not charge?

The alternator will not be able to charge if your belt wears down over time. Fortunately, the broken belt is easy to replace, and can be a quick fix to get your alternator backup and charging again. A broken pulley goes hand-in-hand with the broken belt. The pulleys and belts are part of the system which converts energy into the alternator.

Why does my alternator not charge my battery?

If you’re getting less voltage than that, then your battery is not able to hold a proper charge. Bad Battery Connection It’s possible that if your battery isn’t charging and your alternator is working fine that you have an issue with the terminals, or the wiring connected to your battery.

What should the charge voltage be on an alternator?

Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage

What should I do if my alternator is not working?

The solution is to check your car’s manual for the particular fuse that controls the alternator and replace it. In some cars, you might also find another small fuse to the alternator’s control—usually a 15A to 20A fuse. An alternator does usually has 3 or 4 wires to it to function properly.

Can a car battery be drained by an alternator?

While you might initially think that any problems with electrical things like lights or radio not working are directly related to the battery, the alternator is actually where most of the power in your vehicle comes from. Consider that if you were to leave the lights of your car on overnight by the next day your battery might be drained completely.

Almost all cars with an internal combustion engine contain an alternator as well. When the engine in your car is running, the alternator’s job is to maintain a proper charge in the battery and supply electric power to the vehicle’s electrical systems. The alternator is connected to the engine and is controlled by a drive belt.

Can a bad alternator cause a car to go nowhere?

The ones that fail completely are easy to diagnose. The battery drains and you are stuck with a vehicle that goes nowhere. The challenge is diagnosing an alternator that is just not quite charging like it needs to be. You can easily diagnose it with almost any multimeter. Here’s what to do.

How many volts does an alternator need to charge?

Let’s go ahead and leave the air conditioner off, as well as the headlights and any other accessories. With the engine just fired up, you should get over 14.2 volts. If you got 14.2 or more volts, the alternator is charging fine. If it’s still showing in the 12’s, it’s time to replace the alternator.

What to do if your alternator goes out?

The first thing to check is the battery light on the instrument cluster. This light bulb is part of the alternator field circuit; if it burns out the alternator will not charge. Simply turn the key on and see if it illuminates briefly then goes off. If the light does not illuminate, you’ll need to replace it before continuing.

Why does my Mercedes Benz alternator keep failing?

The alternator charges the battery and provides your car with a constant source of electricity while the engine is running. Over time, the alternator will begin to fail and cause trouble with the various electrical devices in the car.

When to disconnect battery cable to test alternator?

Never disconnect a battery cable while engine is running to test alternator, you may cause damage to alternator or other electrical components from the surge in amperage. If your battery appears to be leaking, then your voltage regulator has probably failed.

What happens if you have a new alternator and the battery is not charging?

The alternator in your car is an integral part of your vehicle’s electrical system. If you have a new alternator and the battery is still not charging, then you definitely have some kind of a problem with your battery that you’ll need to address immediately.

How can I tell if my alternator needs to be replaced?

Also check all wiring between the alternator and battery to confirm wires are in good shape, without cuts, kinks, or visible signs of corrosion. Have an assistant rev the engine up to around 1500 rpms to see if voltage output increases. If it stays the same, the alternator is probably to blame.

What causes an alternator to go over base voltage?

If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

How many coils are on the stator Charger?

The eighteen coils on the stator are actually only three coils, each divided into six parts. In wiring diagrams, the three-phase generator is therefore shown with three coils only. They are connected to form a Y, the ends of the Y are the yellow wires coming out from the rear engine cover.

Why is the alternator light dim at hiatal?

Usually when this is the case, the light will be very dim at hiatal and will get brighter as you rev the engine. To diagnose the problem, put the positive wire of your volt meter on the alternator output terminal and the negative wire of your volt meter on the battery plus terminal.

How does an IDJIT light work with an alternator?

The idjit light essentially goes from the alternator output to the battery positive. If all goes well, both terminals are at the same voltage potential and no current flows. If either the battery or alternator are not at the same level, there will be current flow through the light and it will illuminate.

How does a warning light work on an alternator?

In most modern systems, the electrical current passing through the filament of the warning light is what energizes a circuit in the alternator to start charging.

What does the charge indicator light mean on a car?

Indicator Light On Usually, the first sign that your charging system is in trouble is a “battery,” “ALT,” or “CHARGE” warning light illuminating on your instrument panel while driving. It means that the alternator voltage output is below 12 volts, or over its limit or has stopped charging the battery and your car is running on battery power.

How to check battery and alternator in Mercedes?

The dreaded battery warning light always leaves us not knowing if its the battery, the alternator or both. Watch as I show you how to check the state of these components via the secret diagnostics menu built into your Mercedes vehicle. Haven’t Subscribed? What are you waiting on? Do it today. Loading…

Why is the battery light on in my car?

The cause of the battery light could be a loose or corroded battery cable or other wire connecting components of the charging system, or it might be a problem with the alternator or voltage regulator. The alternator generates the power that is stored in the battery.

Is the control wire on my alternator broken?

As to the OP, there have been a couple members who have had problems with the control wire connector. This is the small connector that plugs into the back of the alternator. Check to make sure the wire is not broken.

What should I do if my Battery Light is intermittent?

You could take your alternator down to most parts shops and get it checked, but it may not show an intermittent charging issue. You can also check all of your connections and grounds to ensure they are tight, clean, and making good contact.

What causes your alternator not to charge?

There are several different problems that can cause your alternator to stop working. Your car’s alternator charges the battery by generating power with a pulley and belt system. If the belt that controls that system snaps, stretches out or breaks, the alternator will stop working, and the battery will not charge.

What causes an alternator of a car to stop charging?

6 Causes of why your Alternator Not Charging Worn out carbon brushes or damaged alternator. The most common reason why your car is not charging is actually because of a worn-out or damaged alternator. Broken Serpentine belt. A closer observation of the alternator will reveal a pulley and belt system that works to convert mechanical energy into electrical energy. Faulty fuse.

Why is the alternator not charging?

– Broken Belt or Pulley. The belt and pulley produce the mechanical power which gets converted into electrical energy by the alternator. Your belt can easily break if it gets stretched out too much, causing it to snap apart. The pulley can also get damaged after a while. In either case, the alternator will no longer be able…

How do I know if my battery or alternator is bad?

Signs of a bad alternator. If the above steps reveal that the battery is working, it’s time to take a closer look at the alternator. There are certain signs of a bad alternator to look for: While running the car, note the brightness of the interior lights. If the dashboard gradually dims, the alternator is likely at fault.

What happens if you start your car without an alternator?

If you were to try and start your vehicle without an alternator, the battery alone would not be able to produce enough power to get the engine running. Even if you had a new car battery and were lucky enough to turn the engine over, it would probably run for about 10 minutes before the power cuts out.

What should the voltage of an alternator be?

You can easily test the voltage by connecting a voltmeter to your battery while the engine is off. The voltage reading should be between 12 and 13 volts. You can automatically assume there’s a battery problem when the reading is lower.

Why does the alternator only work in one direction?

The resistor only allows voltage to flow in one direction to the alternator. If the resistance increases in the resistor, or if the resistor allows voltage to flow in both directions, it takes longer to excite the alternator which causes a delay in operation.

How often does a car alternator need to be charged?

Alternators and batteries do not last forever, and each have their own lifespans. A car battery will last from 2 to 5 years, depending on how often you drive and the climate where you live. Batteries generally last longer in colder environments and shorter in hotter environments. Alternators will last about 7 years or every 80,000 miles.

What happens if the alternator in your car fails?

If it breaks and the components in your car’s electrical system are going to have a spotty ability to continue working if they work at all. If the voltage regulator in your car completely fails, then the battery can no longer be charged by the alternator and it will soon lose its charge and die.

Why would a good alternator not charge a battery?

The alternator is powered by several different wiring mechanisms. If a wire is not attached properly, becomes detached or is inadvertently cut, the alternator will not have any power. If the alternator is not getting any power, it cannot turn the pulley and belt mechanism that charges the battery, and the battery will not charge.

Why is your new alternator not charging your battery?

The most common reason for an alternator not charging a battery is because of a bad alternator or battery . You can easily test the voltage by connecting a voltmeter to your battery while the engine is off.

Will a car with a bad alternator start with a new battery?

A bad alternator can prevent a car from starting because it did not charge the battery when the car was running. However, even if you have a dead battery because of the alternator, you can still jump-start the car using the following method.

Why does your battery light keep coming on?

There are a few different reasons why your vehicle’s battery light came on. It could be a problem with your alternator, which recharges your battery while your engine is running. It could also be a wiring issue such as a damaged or disconnected wire affecting your battery.

Navigation