Car Lights Won’t Stop Blinking? 6 Reasons (Solved)

In a well-functioning automobile, the headlights should provide stable lighting. Drivers and other road users can be distracted by a headlight that fluctuates or blinks because it creates a distraction on the road.

Here you will find out why your headlights may be blinking.

What Causes Headlight Blinking?

Headlights that won’t stop blinking can have a defective bulb or have an issue with the headlight circuit. The problem can also be linked to the failing alternator or there could be a situation in which only one headlight is non-stop flashing or blinking.

All of the reasons mentioned in this article apply if one or both car headlights won’t stop blinking or flickering.

1-Failing Bulb

A failing bulb can be one of the reasons that the lights won’t stop blinking.

If halogen bulbs are installed in the car’s headlights, the filaments may be worn out or damaged, which would explain the blinking.

Halogen headlights don’t typically blink in that manner, but it is possible because if the filament is broken into two parts, the ends may occasionally come into contact and generate a fluctuating or blinking condition. Although, this can be a rare case and does not happen with every car.

There is a wide variety of headlight bulbs installed in different cars, and each has a distinct estimated lifespan.

Since halogen headlights frequently turn hot, they typically have a shorter lifespan and will malfunction more quickly than other types.

Halogen bulbs are most likely to be used in the headlights of an older car or even a modern but mid-range model. It’s not certain that a halogen headlight will start blinking or even need to be replaced because halogen bulbs commonly last over 99,000 miles. whereas headlight bulbs are available from spare parts providers if they do fail.

Light-emitting diode (LED) lights or high-intensity discharge (HID) headlight bulbs have a longer lifespan. These headlight bulbs are commonly installed in more expensive car models. The problem with them is that they can experience light-related malfunctions that make them dim and LED lights often blink as they get close to the end of their useful lifespans.

Changing the headlight bulb will help solve the headlight blinking problem.

2-Problematic Headlight Circuit

A circuit issue may potentially be the cause of the non-stop blinking headlights. For instance, the problem might be an indication of faulty wiring or a bad connection.

A defective headlight switch may also be at fault.

Older automobiles’ headlight switch systems have a built-in circuit breaker. That circuit breaker makes the headlight blink or flick on and off when a short circuit happens.

Older models of cars have a tendency to experience headlight blinking issues because of circuit failure, although the headlight switch circuit breaker normally lasts the lifetime of the car.

Driving late at night when the headlights suddenly stop working can be frightening and dangerous. Therefore, to prevent a complete, unexpected loss of the headlights, a self-resetting circuit breaker is installed in the light switch of older automobiles.

In the older automobiles from the 1970s to 2000, if a short occurs in the ground connections, particularly the wire going to lead to one of the headlights, the inner circuit breaker would then continuously open the circuit and close it.

As a result, the headlight will continuously blink off and on, providing sufficient lighting to either reach a safe place or leave the road.

Moreover, if both headlights are blinking in this manner rather than just one, it usually indicates that the circuit breaker has worn out to the point where it can no longer sustain the regular voltage of the headlights and that a new headlight circuit breaker is required.

Normally, this type of failure won’t occur unless the headlights have been turned on for a long time since the heat from the lights will cause the malfunctioning of the circuit breaker.

Keep an eye on how long you drive when the blinking starts, if it happens every single time at the same distance coverage means the circuit breaker in the switch is failing.

Modern cars may have a circuit breaker outside the switch, but most of the time, each headlight bulb has four filaments, of which two are bright and two are dim, connected separately with four fuses. In this manner, the remaining filaments will continue to function even if a short develops in a wire connecting to one of them.

A professional can help to sort out the circuit issue for the blinking headlights.

3-Failed Battery


One of the most common causes of blinking headlight bulbs, dashboard lights, and other lights in your automobile is a failed car battery.

Blinking headlights may be one of the warning signs that an automobile gives when its battery is almost dead. The headlights of the car may fade or blink if the battery is insufficient or unable to supply adequate power. Of course, in the event of battery failure, the car may give other indications before the headlights won’t stop blinking.

An examination of the battery terminals and testing of the battery should come first in the diagnosis of a headlight blinking.

Car batteries usually have a lifespan of three to five years. However, a number of factors, such as the state of the car, driving style, and local weather, may influence how long the battery lasts.

Examine the battery’s acid level and do a charge capacity test.

A mild blink in the lighting system could be caused by a battery that is no longer able to charge properly. If the car’s battery is completely drained, replacing it with a new one will solve the headlight blinking problem.

Always use proper protective eyewear that goes beyond ordinary eyeglasses when working around a car’s battery. Always have fresh safety glasses on hand since batteries can explode and eye injury is permanent.

4-Failing Alternator

The alternator transfers power through the car’s electrical systems while you’re driving and also recharges the battery. The battery powers various components of the car, with the help of an alternator, including the radio, speakers, heated seats, wipers, power windows, and more.

When the alternator starts to malfunction, the car’s electrical power decreases. This may cause the headlights to non-stop blink or dim because they are powered by the car battery.

The electrical system of the car rapidly depletes when the alternator fails to charge the battery.

The voltage regulator, which is commonly placed inside the alternator, or the alternator itself, may have a problem if the headlights are continuously blinking. Such charging system issues could result in irregular current output, which could cause the blinking of the headlights.

If the alternator is faulty, there may be additional symptoms.

Some other indications of a defective alternator include, frequent car stalling, battery-lighting warning signal, lights that are too bright or dim, whining or growling sounds, vehicle starting issues, accessories are slow to work or malfunctioning, and if the alternator has seized, there will be a burnt rubber smell.

If this happens, take the car to a professional technician to examine the damaged alternator to see if it can be repaired or if it needs to be replaced.

5-Faulty Wiring

Sometimes, physical damage to the wiring systems causes the car’s headlights to blink.

It is common that wires are likely to wear out, become brittle, or melt in hot environments. Rarely, the wire may start to separate from the connections, creating a weak connection.

To fix this problem, it could be necessary to replace the defective wires.

The wiring is a sensitive component of a car and dealing with the faulty wiring also necessitates disabling electrical components. It is better to get help from a qualified professional. Any disturbance in the wiring can cause other problems in the car’s functionality.

6-Switch Malfunctioning

Blinking headlights on the car could be a sign that the electrical system and computer system of the car aren’t interacting.

In rare cases, a malfunctioning switch, typically on headlights, could be the root of this problem.

A new headlight switch can be installed to remedy this problem. Alternately, it may require a thorough examination of the car’s computer or electrical system, which includes the fuses, alternator, relays, and battery.

Visual Examination

To understand your car’s headlight blinking issue, A visual assessment should be done as a first step.

Look for problems like a burnt headlight bulb, faulty wiring, electrical or battery connections that are loose and headlight socket damage.

Fixing Blinking Car Lights

After going over the most common reasons why car lights won’t stop blinking, it’s time to concentrate on the problem’s root cause and start troubleshooting.

The following are some of the steps that can be taken to fix the headlight blinking and protect the car from further damage.

  • Verify that the alternator is functioning properly. In this situation, you need to solve the problem immediately by taking the car to the mechanic.
  • Check any unstable or loose cable, wire, fastener, or ground connections, particularly the ignition wires, to see if that fixes the issue.
  • Use a voltage regulator to check the batteries in the car to make sure they are charging properly. The normal voltage should be between 13 and 15 volts. If the voltage is proper, then look for other potential causes.

Using the Scanner

These steps can help identify a damaged headlight by using a scan tool:

Turn on the car headlights using the bi-directional instruction through the scan tool. If the lights turn on, it suggests the headlight circuit is not the cause of the headlight blinking.

It indicates that the particular controller that controls the headlight is most likely the cause of the issue.

By using a headlight circuit schematic, determine where the open circuit is by checking the voltage at various components. Make sure to constantly follow the car’s manual instructions for this step.

  • A high battery voltage may be the reason why the headlights seem brighter than usual. One headlight is about to fail if it is the only one that is brighter than usual. Verify that the charge system voltage is below 16 volts, which is the norm for most automobiles.
  • Indicators of high circuit resistance include a loose electronic circuit, a rusted socket, or a bad electrical ground connection. These indicators cause the dimming of the headlights compared to normal.
Was this article helpful? Like Dislike

Click to share...

Did you find wrong information or was something missing?
We would love to hear your thoughts! (PS: We read ALL feedback)