Headlights And Dash Lights Flicker When Car Is Running

If the headlights and dash lights are flickering, then there will be an electrical problem in the car. Driving with these headlights and dash light is not safe for you. It creates a distraction while driving, and the other driver also gets confused.

Flickering indicates vehicle problems, but it is difficult to find out the exact cause without a professional mechanic. They use suitable tools to scan electrical problems. But there are some common reasons for this problem. In this article, we will explain why the Headlights and dash lights flicker when the car is running.


4 Reasons for flickering headlights and dash lights

The vehicle’s dash lights imply the condition or fault issue, and headlights provide lighting in the dark. So it is necessary to work these lights properly. The flickering light is a matter of consciousness, and it should be repaired as soon as possible. There some causes that lead to lights flickering:

1. Alternator fail

An alternator is a central part that is connected with the electric system of a car. The alternator supplies the power to start and run the car. If this part isn’t in good condition, it can damage the other parts. Alternator failure can be the main reason for the headlight and dash light flickering.

Since the alternator helps to animate the electric system, its failure directly affects the lights of the vehicle.

Lights flickering and later becoming dim clearly indicate the alternator malfunction. Repairing or replacing the alternator can be expensive. There are other symptoms that specify the alternator damage, such as power seats and windows will work slowly, hear odd sounds, or bad burning smell.

2. Circuit problems

To power up the headlights and dash lights, they connected with the electrical system through a circuit. So if there is any damage to the wiring connection, it can affect the lights and start flickering. Maximum old car’s headlights are connected with a built-in circuit breaker. If it gets some short circuit, the headlights will be flickered.

Bad headlights are also responsible for flickering. The old car has a halogen bulb then the filaments can wear out and cause flickering. This type of bulb has a short lifespan and fails faster. If the light started flickering, it should be replaced. Today’s high-end vehicles feature LED or HID lights that give a pretty much longer lifespan.

3. Weak Battery

If the car battery is about to run out of charge or it is near the end of its life, then the headlights and dash lights become flickering. A car battery is rechargeable, and an alternator helps to keep the battery charged. A poor battery can not give enough power to the headlights, and they come about dim or shut off. 

An alternator can not bring back the dead battery; it should be replaced. Moreover, a weak battery can run the vehicle, but the lights will be dim after some time.

A car battery can go almost 4 to 5 years. The actual lifespan depends on the driving condition and weather. If the alternator or circuit doesn’t have any problem, it can be the time for a battery renewal. 

4. Overstressed Wiring

Stressed or incorrectly placed wiring can cause headlights and dash lights to flicker. The wires will be stressed because of excessive heat from the engine, or they can wear out. When the wire is stressed, it creates resistance for supplying proper voltage.

Sometimes the headlights are stopped working because of overstressed wiring. So replacing the overstressed wiring, you can prevent the headlights and dash light from flickering. 

Applying scan tool to find the problems quickly

If you have some factorial tools, then you can easily find out the flickering problems. The scanning tool has a defective sensor that helps to find the problems quickly. So here are the steps to follow:

  • First, turn on the headlights using the scanning tool. It will be in bi-directional command. If the lights don’t turn on, then it will be for headlight damage. On the contrary, if they turn on, then it will be the input control system that means battery or alternator damage.
  • Open the circuit and measure the voltage at different parts because varied voltage can make a difference in lighting. The lighting can be brighter because of the high voltage that extracts more power and shortens battery life. The voltage should be 15.5 that is standard power in most vehicles. And if the voltage is short, then it will cause the light to be dim and flickering.

Frequently Asked Questions (FAQ)

1. Can a bad battery cause dash lights to flicker?

Yes, it can because the dash lights are connected to the electric system of the car. And the car gets the electric power through the battery. If the battery is bad or dead, the dash lights will be dim and flicker. It would be best if you change the battery rapidly before damaging the other parts. 

2. How do I stop my headlights from flickering?

The flickering headlight can be dangerous and cause accidents. If the headlights fail, quickly remove them and place them with new headlights. Changing the damaged bulb is very challenging. If you don’t do that earlier, then go for a servicing center. Headlights flickering can occur for other problems too, like alternator failure or lousy battery. So repairing these problems, you can stop headlights from flickering. 

3. Why do my headlights flicker when accelerating?

If the headlights flicker when accelerating, it may be because of worn-out alternators. A poor alternator can not provide sufficient power to light up the headlights properly. It is time to replace the alternator. 

Final Words

Headlights and dash lights flicker when the car is running can be a serious issue. Sometimes severe accidents can occur that can harm anyone’s life. If you see any flickering in the headlights and dash lights, find out the reason and repair it as soon as possible. You may not be aware of the repairing process, then go to the repairing service center immediately.

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