Ford F-150 Battery Light Comes On And Off?

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No wonder as a pickup truck, the Ford F150 is renowned as the all-time best-selling vehicle all over the United States.

However, it does have some exceptional features and enhanced driveability that make it stand out from the rest.

Lately, I see some problems, i.e., the battery light is going on and off. However, when you see the battery light on in your F150, it could be due to many few possibilities.

Here is why this is happening to your Ford F-150 below:

  • Battery Charging Issues: Your battery light will be on when there are some issues with the battery charging. Although a F150’s charging system is pretty simple, perhaps these light issues can be caused due to a faulty battery or a malfunctioning alternator.
  • Low Voltage: Another reason for your battery to be on is when you have low voltage in your car. Every car requires a certain amount of voltage to work. This is most common with vehicles that have a very old battery in them.
  • Faulty Battery: It is not uncommon to see an F150 struggle to get a good start, and the battery light remains on after that; this is a clear indication that you may have a faulty battery.

Let us take a closer study of why the battery or charging system lights are turned on sometimes.

What Causes Your F-150’s Battery Light To Come On And Off?

What does the battery light mean on your f150

Let us have a closer look at what makes the battery light go on and off below:

1. Battery

The prime component that is needed to start any automobile is the battery.

Just after the vehicle is started, the alternator begins to run. Once the alternator starts, it charges the battery.

If by any chance you have a faulty battery, the F150 will struggle a lot to start. This is a strong indication that you can no longer use your battery. You have to get it replaced.

2. Alternator

You can quickly figure out that you have a malfunctioning alternator.

For example, you have a malfunctioning alternator if you see the battery light is on and the engine of your F150 is running.

When this happens, it gives a clear notification that your alternator cannot provide the wattage required by your battery and power to the other components as it should.

Do not neglect this; getting a new alternator will fix this issue.

3. Belt Of The Alternator

For moving the alternator, today’s modern automobiles are using a serpentine belt.

Experts say it is more powerful and way more capable of moving the alternator more effectively than any other car component such as the power steering or the AC compressor.

If this belt gets damaged by any means, it will not move the alternator and get a sufficient charge out of it.

4. Corrosion On The Battery Post

Every automobile needs an adequate amount of charge or energy to run, and this energy is generated entirely from the Alternator’s voltage.

The generated energy or voltage is passed using wires which are connected to the battery’s post.

If you have the battery post corroded, the alternator will not give sufficient voltage to the battery.

When the battery does not get its required voltage, it makes your battery light turn on.

However, it is not a crucial issue, you will be able to solve it all by yourself, and all you need is brush and battery post cleaners.

But be cautious, the corrosion shouldn’t come in contact with your eyes, or you can seek help from a professional.

Detect Your F-150 Battery Light Issues

The battery light on/off indicates problems with the alternator and battery.

So, when you see your battery light is on, you have to perform a voltage and battery test to ensure which component is creating this ‘on and off issue.

1. Voltage Test

To know if the alternator is damaged or flawed, you need to do a voltage test.

To be able to do that, you need a good multimeter and follow the procedures as directed below:

  1. To do a proper reading, you are required to set the multimeter to 20V DC.
  2. After setting the multimeter, turn off your Ford F150 and connect the device.
    It would be best to connect the negative tester to the battery’s negative terminal and the positive tester to the positive terminal to make a secure connection. With the engine turned off, you will read about 12 volts and 12.6 volts in your multimeter.
  3. In this third step, you need to turn on the engine but make sure your AC, headlights, backlights, and other accessories are turned off.
  4. Now, look at the multimeter and see if it shows 14.2 volts. If the multimeter reads 14.2 or more than 14.2 volts, then your alternator is fine, and there is no need to get it replaced.
    However, if you get a reading under 12 volts, you must replace your alternator with a new one.
    Or, if the multimeter reads 13 volts, you need to get the alternator checked by a professional. Then, perhaps, there might be an issue with the alternator that can be resolved.
  5. In this step, you need to re-establish the connection, i.e., connect the positive and negative testers to the respective terminals of the battery. The only difference is, you need to test the voltage with all the accessories like radio, lights, and AC turned on.

Now, if the multimeter makes a reading of the voltage of 14.2 volts, your vehicle’s alternator is safe and working correctly. But if it reads 12 volts, then you need to get the alternator replaced.

2. Battery Test

If you get proper readings for the alternator, it means the alternator is fine. To check the battery, you should contact your local store.

Half of the time, they get the battery tested for free. And if they find your battery is the culprit, and they will get the old battery replaced.

How To Reset Battery Light On Ford F150

Battery issues do not always mean that they ought to be replaced; what if there is still something to resolve.

So yes, you can further examine your F150’s battery by troubleshooting it.

To troubleshoot, follow the steps as directed below:

  1. Look if there is any corrosion near the battery terminals, as they can create problems conducting electricity.
    To see, gently remove the cover of your vehicle’s battery and if you get to see a greenish substance near the terminals.
    If yes, that’s corrosion. Corrosion occurs from regular use of your vehicles, and it is pretty standard. Keep yourself from touch the battery with your hands.
  2. If you see corrosion near the terminals or on the battery, this might be the reason for the battery light.
    To clean the terminals, you will need a brush, hot water, and elbow grease. Then turn off your engine, remove the battery cover and detach the wires. Next, apply the oil and scrub it gently with the brush.
  3. At times, the battery light is turned on due to a feeble connection between the battery and connected cables.
    When you check the battery, check if the clamps are tightly connected to the respective terminals.
    If you see they are a bit lose on the clamps, you can tight them using a wrench or pliers.
  4. Before you reset it, check all the components like the alternator and its belt. It should be the primary fix. If you don’t fix it before resetting your battery, your battery will end up dead.
  5. The last and final step, to reset your battery light, you need to configure your F150’s computer system. First, you need to get to its diagnostic information.

After that, you will have to remove all the connections to the battery. After disconnecting, go to the truck’s home screen and charge the battery using a data stream.

And customize another battery setting like temperature, voltage, charge, etc. And now your battery light has been reset.

Frequently Asked Questions

Q1. Will It Be Safe If I Drive My F150 With The Battery Light On?

If there is any problem with your vehicle’s battery or alternator, you will notice the battery light is turned on. I advise you not to drive when the battery light is turned on.

Because the vehicle can shut down on the roads without warning, there is a chance for the vehicle’s battery to die and not start again.

If you the light on after the vehicle starts, keep yourself from driving it and get this checked immediately.

Q2. Can A Faulty Alternator Damage A Freshly Installed Battery?

Under any circumstances, do not use a freshly installed battery along with a faulty alternator. It can entirely damage the brand-new battery.

Q3. Are There Any Other Symptoms Of Faulty Battery Or Damaged Alternator?

Yes, apart from the battery light, some other symptoms can help you identify the problem.

Symptoms Of A Bad Alternator

  • Metal crunching, rumbling, or squeaking sounds.
  • Accessories like AC, radio, and lights won’t turn on.
  • The engine won’t start (You may also want to know Why Your Ford F-150 Won’t Start).

Symptoms Of A Bad Battery

  • Faint or low headlights.
  • Dim lights on the interior.
  • Interior lights can work, but the engine will struggle to start.
  • Car accessories will start malfunctioning.


Throughout the article, I have stated all the probable reasons for your Ford F150 battery light comes on and off.

But, as I have mentioned before, when the light is on, there can be many possibilities.

In this article, we have discussed the causes and the solutions that can help fix this issue right away. I have also provided a way to troubleshoot or reset your battery light.

I hope this article has helped you learn the causes and how to reset your car battery light.