How to fix flickering LED Headlights

how to fix flickering led headlights

Car manufacturers have taken headlight bulb production further by creating LED (light-emitting diode) headlights for vehicles. Unlike halogen lights, LED headlights offer longevity, promote better visibility, and are energy efficient in addition.

They are really fantastic on automobiles until they start to flicker.

Now flickering headlights can lead to potentially dangerous situations, so you might want to fix them as soon as you can. That’s why you need to learn how to fix flickering LED headlights.

This article walks you through the process of fixing your vehicle’s flickering LED headlights. Let’s start with why LED headlights flicker.

Why LED Headlights Flicker

There are a few reasons why you notice your vehicle’s LED headlights flickering. Here are some of them:

Communication issues

Your car’s headlight electrical system and the car computer system interact to get the headlights working optimally. When there is a problem with this interaction between both systems, you will likely have flickering LED headlights.

CAN-bus system issues

The Controller Area Network or CAN-bus system conveys messages across the devices and components that enable your car to function optimally.

You might need to check the state of the car’s CAN-bus system to ascertain if it’s responsible for the flickering LED headlights.

Problems with the electrical power supply

LED headlights are powered by an electrical current from the car. So inadequate or unreliable electrical supply from your car can cause your LED headlights to flicker.

One reason for this level of electrical power supply is a weak or failing vehicle battery.

Another reason is the alternator. Vehicle alternators come with voltage regulators that regulate electrical current output and keep it consistent.

Like with all components, these alternators go bad, and once that happens, the headlight’s power consumption is affected, which causes the headlights to flicker.

Bad LED bulbs

Like the regular LED light bulb in your living room, your car’s headlight bulbs can go bad once it has completed its lifecycle. An LED bulb can also go bad when it is physically damaged.

Once a LED bulb goes bad, there is a tendency for the headlights to flicker.

Wiring system issue

You might have flickering LED headlights when there is a problem with the vehicle’s wiring system. Some of the usual suspects are stressed wires or poorly connected fuses and connectors.

Wiring issues can cause a headlight circuit issue like short-circuiting (especially in older vehicles), which causes the headlights to flicker.

How To Fix Flickering LED Headlights

Now that you understand why LED headlights flicker and how to diagnose such situations let’s look at how you can fix the issues.

Get new bulbs

As you already know, one of the causes of flickering LED headlights are bad LED bulbs.

Once you have made your diagnosis and have ascertained that it is the issue, your best bet would be to get new LED bulbs to replace the bad ones.

To do this, start by taking away the headlight protection cover to gain access to the bad bulbs.

In some instances, the bulbs might just need to be firmly attached if they are loose.

Fix the power supply

Having uneven currents is bad for your LED headlights as they can get damaged by irregular power.

Flickering LED headlights are often an indication that your LED lacks the correct quantity of power.

In this situation, your best bet would be to install an LED driver with LED headlights, as this guarantees steady voltage. LED drivers also come in handy when your car has an old wiring system.

Another way to fix the power issue is to replace the alternator if it has gone bad. You also want to replace the car’s battery if it has started to fail.

You might need professional help with the alternator but replacing the battery is something you can handle yourself.

Use a load resistor

You could use a load resistor(s) to fix flickering LED headlights because it provides LEDs with enough current to power them.

It also serves to help manage the extra volume of current and improves the communication between the car computer system and the electrical system.

So with a load resistor, you get to solve two issues (electrical power and the communication issue) at once.

Deploy a LED decoder

Like the load resistor, the LED decoder can come in handy when looking to resolve a flickering LED headlight. It is designed to electric current, which it then dispatches consistently.

LED headlights often flicker when the power supply is not steady. LED decoders fix that issue by being able to supply the electrical power steadily.

Fix the wiring and electrical accessories

The wires that are attached to the LED headlights play vital roles in how it functions. Any issues with them will cause flickering.

So once you have noticed that there is some damage to the wiring system or electrical accessories, visit a mechanic to get it fixed ASAP.

Use anti-flickering adaptors and warning cancelers

Another way to handle the communication issues is to use anti-flicker adaptors or warning cancelers.

Either of these devices improves the communication between the car’s computer and the LED headlights.

The anti-flicker adaptor also helps in managing several wiring issues. The caveat is that you need to install the right type for it to function optimally.


Why are my LED headlights flickering?

There are quite a several reasons for which your LED headlights are flickering. CAN-bus issues, bad LED bulbs, power issues, or wiring issues can cause your car’s LED headlights to flicker. The good news is that none of the problems are expensive to fix, and you can efficiently resolve them when you want to.

Is it wrong for LED lights to flicker?

Yes. Flickering LED headlights may not affect the engine’s performance, but they can be risky to drive around with. This is because they will affect your visibility at night or in extreme conditions when you have visibility issues. We advise that you get them checked out and resolved as soon as you can.

Does anti-flicker adaptor help with LED headlights?

Yes, it does. As the name suggests, the anti-flicker adaptor is designed to counter flickering in LED headlights. It does this by improving the communication between the LED headlights and your car’s computer. Ineffective communication is often one of the reasons behind flickering LED headlights.

Can I fix flickering LED headlights myself?

It depends on the cause of the flickering. Someone without professional mechanical training might easily handle instances like a weak battery or a loose electrical accessory. However, running comprehensive diagnostics and addressing wiring issues will require a professional mechanic.

How do you diagnose flickering LED headlights?

There are two ways to do this: manual inspection and deploying a scan tool. With the manual method, you look for telltale signs like loose wiring/electrical accessories, faulty headlight bulb(s), broken headlight socket(s), and damaged wires. Deploying a scan tool will require a certain level of skill, the vehicle’s repair manual, and a factory-level scan tool to check the lighting circuit. If you are finding it difficult, call for a professional assistant.

Final word

LED headlights are great on vehicles because besides making cars look better, they improve visibility and ultimately enhance your driving experience.

The downside is that the LED headlights might flicker, which can be a risky situation when driving. So knowing how to fix flickering LED headlights is extremely important.

The article describes some ways to handle such a situation if it arises so that you can fix it yourself without going to a mechanic garage.