Why Do My headlights Flicker On My Car?

Headlight flickering can be very annoying and bothersome. It can also be very dangerous when you are on the road. In this article, I will share with you some of the causes of a car headlight my flicker, and solutions for fixing it.

The reason why your headlights may be flickering may be due to one of the following below;

  • Loose Connection Or Fuses
  • Bad Wiring System In Your Car
  • Dying Battery Of Your Car
  • Low Quality LED Light
  • Defective Alternator
  • Loose Bulbs
  • Worn Out Light Bulbs or Lamps
  • Faulty Headlight Switch
  • Improper Dimmer Setup
  • Unstable Electrical Supply From Your Car
  • High Wattage Electrical Appliance
  • The Miscommunication Between Car System And The Headlight Electrical System

To learn the details on why headlights flicker, keep reading this article.

1. Loose Connection Or Fuses

When a headlight flickers, it means that there is a loose connection, or the fuse is not installed properly. This problem can be found when you are driving on a road with bumps or rough roads. This type of problem can be very difficult to detect.

Your vehicle’s wiring is the most important thing to consider if you have loose connections that are causing your lights to flash. This is because the electricity is not being passed to the bulbs well and causes your headlight to flicker. This can also cause the bulb to overheat and burn out.


It is better to check the wiring and switches if they are damaged or loose. It is better if you take your car to an electrician who can easily identify the problem and provide a solution immediately. Or you can buy an anti-flicker adapter that can help to indicate the miscommunication between the system and the LED light.

2. Bad Wiring System In Your Car

Your headlight may begin to flicker due to physical damage to the headlight components. The inside of the connector may begin to melt and cause a poor connection to the bulb. Sometimes the wire can pull out of the back of the plug, causing a bad connection.


You may need to replace any damaged components. Since this process requires an overview of all electrical components, it is better to hire a qualified technician who can do it without causing further damage.

3. Dying Battery Of Your Car

A dying battery can be one of the most common causes of headlight flickering, as your headlight relies on battery power to function well. A weak battery can lead to flickering or dimming headlights.

You need to know that your car battery can last for three to five years if treated well. Keep in mind that frequent short trips, parking for long periods of time without turning on the vehicle, many electrical accessories, or climates that are too hot or very cold can shorten battery life.


Take your car to a technician who will check the battery. If the battery is the cause of the headlight flickering, you’d better buy a new battery.

4. Low Quality LED Light

A high-quality LED light is very important to avoid your headlight flickering. A high-quality LED light offers benefits like brightness, durability, stability, and better performance.

So, it is always better to buy a high-quality LED light to avoid problems like the flickering of the headlight. You need to avoid an inferior LED light to avoid headlight flickering and other damages.

Usually, the inferior LED light will produce too much or low brightness that could cause flickering.

Since we have three types of chips such as COB, CSP, and SMD, which have different qualities, you need to choose the best chip that best fits your car.


Make sure you choose the best brand and original products and avoid buying aftermarket products.

5. Defective Alternator

If the alternator is faulty, the electrical output of your car will be affected, which can cause the headlights to flicker and stop working properly. Since the headlights depending on the battery, if the alternator is faulty, it will not be able to charge the battery, which will cause the battery to be discharged.


Have your car checked by a specialist and fix the alternator problem.

6. Loose Bulbs

Loose bulbs occur when you do not fix the bulb properly. If the connection between the bulb and the socket is poor, the power supply will not be able to regulate the current, which will affect the power transmission and lead to electrocution.

The loose connection of the bulb increases electrical resistance and heat, which can cause the LED light to flicker and burn out the bulb.


After you have repaired the lamp, make sure the bulbs are tightened again to avoid unnecessary damage and flickering. This can help keep your bulb from burning out before it reaches its lifespan.

7. Worn Out Light Bulbs or Lamps

If your light bulb or lamp is old, worn, and damaged, it can cause your headlights to flicker. The good news is that this problem can be easily fixed by taking your car to a technician and replacing the bulb, or if you know the steps, you can do the replacement yourself at home.

8. Faulty Headlight Switch

Your electrical system and your car’s computer system need to work well together. If they do not talk to each other, your headlights may flicker. A faulty headlight switch can cause your headlights to flicker.


You can take your car to a technician and have a new headlight switch installed, or you may need to take a deeper look into your car’s computer or electrical system, which may include the fuses, switches, battery, alternator, and relays

9. Improper Dimmer Setup

All the dimmer has a switch that allows you to adjust the brightness to your liking. You can either increase or decrease the brightness depending on whether you want a high or low beam.

You need to be aware that the type of light you have will determine the type of dimmer switch you can use. You need to make sure that you choose the right dimmer switch to have a good combination and avoid a wrong dimmer switch that can cause damage to your dimmer electronics, light bulb, and flickering.

If you buy an inferior dimmer or a counterfeit product, the current and voltage delivered to the bulb can cause damage and reduce brightness.

Also, an improperly adjusted dimmer can get stuck on a feature and fail to regulate the light, eventually causing the headlight to flicker.


Make sure your light and dimmer switch are compatible and set correctly to avoid miscommunication between the dimmer and light.

10. Unstable Electrical Supply From Your Car

The unstable power supply is one of the factors that can cause your headlight to flicker. Therefore, it is very important to have a stable power supply for your light that can guarantee a constant power voltage for your LED light because LED light depends on a constant power voltage for your light to work properly.

The input and output should be stable to be able to control the voltage. If the voltage cannot be controlled, the power supply will be damaged and the current to the LEDs cannot be regulated.

The excess current will cause the LED light to flicker because the brightness fluctuates and high internal heat is generated, which can cause the LED light to fail.


This problem can be solved by installing a driver in the headlight that can provide the stable voltage required by your LED headlights.

11. High Wattage Electrical Appliance

Any accessories with high current sources like battery and air conditioner can cause the headlights to flicker if the car has lights that have a high wattage than your power supply. Make sure you install a high-wattage bulb to avoid damage.

For example, if you have a high wattage device of 15 to 20 AMP and other devices with the same wattage such as air conditioner, car audio amplifier, radio amplifier, if they are all used together, it can cause the headlights to overload and eventually flicker.


It is better to use the power supply to regulate the voltage going through

12. The Miscommunication Between Car System And The Headlight Electrical System

Miscommunication between your car computer system and the headlights’ electrical system can lead your headlights of the LED to flicker.

If there is a discrepancy between these two can cause a problem. The electronic frequency and output of the LED light are different from that of the conventional light, which can cause flickering problems.


This problem can be solved by devices such as anti-flicker adapters, LED decoders, and warning cancellers. These devices act as a language translator, bridging the miscommunication between your LED headlight and your car’s computer.

Anti-Flickering Equipments You Can Use For Your Headlights

To avoid the flickering of the headlight, we can use the following anti-flickering equipment.

LED Decoder

This is one of the best decoders that can prevent headlight flickering. This LED decoder has a large capacity and can store electricity inside and releasing it in a stable manner.

The new cars are have been installed with pulse power, which has a technology that can reduce the heat of halogen bulb and their power consumption by providing intermittent current.

This is a better decoder because it is environmentally friendly and energy-saving.

Load Resistor

This is another device that can be used to fix flickering problems. After replacing halogen bulbs with LED, less and less power is consumed because the LED bulb generally requires less power to function properly.

Load resistor devices are designed to solve this problem by compensating for the lower power draw.

This can play a role when you convert halogen bulbs to LED lights, which is the decrease in power because generally LED light requires less power to function compared to halogen bulbs, so if you use the load resistor it will help your car’s electric bulbs system to work efficiently.

Final Thoughts

After seeing the causes of headlight flickering and the solution, we need to understand, with the current technology it is easy to get a hold of devices that can solve the flickering problems. In addition, make sure you are aware of your own car’s technical characteristics to determine compatibility issues before fixing this type of problem.

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