Why Does The Same Headlight Keep Burning Out?

What if you’re driving home late one night and you notice that one of your headlights is burned out. Which will keep you anxious by thinking overall, “why does the same headlight keep burning out?

This is obviously a concern, driving at night or in inclement weather with just one headlight is dangerous. Learn how to deal with this problem in this article.

Causes: Why Does The Same Headlight Keep Burning Out?

The primary reason your headlights keep burning out really comes down to either you are touching the bulbs when you are installing them into your assembly, or there is quite possibly a bad wiring connection somewhere along the line of your headlights. Read on to learn some causes of premature headlight bulb burnout.

1. Loose Wiring Connection:-

Because of loose wiring, the flow of electricity to the contact point with the bulb will not be quite right, and will actually cut off, and back on at fast intervals. The constant on and off will cause the bulb to get heated up. These fluctuations in the electricity flow cause the filament inside the bulb to go bad, and break, causing your headlights to no longer work.

2. Touching Bulb While Installing:-

However, traces of dirt or grime and moisture from your skin while fitting a new bulb might cause uneven heating around its surface. As such, there is a structural failure in the bulbs and they might get explode.

3. Excessive Vibration:-

Vibration caused by driving over rough roads, potholes, and bumps will reduce the filament lifespan. The halogen filaments inside the bulbs can’t withstand excessive vibration. Another cause of vibration may be a fault in your headlight structure. If the bulb is not securely mounted in the headlight assembly, it will vibrate, even under normal driving conditions. Insecure mounting may be the result of a bent bulb socket or headlight housing.

Similarly, if the headlight housing is not securely attached to your car, the entire housing, including the bulb and filament, will vibrate while you are driving, shortening the filament lifespan.

4. Condensation Inside The Headlights:-

Because of excessive condensation inside the headlights, there could be electrical shorts. As such, it reduces the lifespan of the bulbs and so you should check if there is too much dampness inside the housing.

5. Faulty Voltage Regulator:-

A voltage regulator is an important piece of electrical device for a vehicle. In short, it limits the maximum amount of voltage that flows through the whole wiring system. That way, it provides a safe and usable amount of electricity for the components to use. Therefore, if you are having issues with your voltage regulator, chances are that it might impact your headlight bulbs. That’s because the flow of electricity won’t be constant and it might blow the bulb’s filament.

Therefore, these are some basic causes for your question “why does the same headlight keep burning out?

How To Deal With The Same Headlight Burning Out Issue?

To solve this issue of headlight getting burnt out you should try the following below-mentioned steps:

Step 1:-

Sometimes, vibration caused by the vehicle can loosen the headlight. So, it is wise to check all the bolts connecting to the headlight are tight and no mounting is cracked around the headlights. Also, check whether the electrical connectors that hold the bulb are secure. Or else It is a good idea to fit new connectors to the bulb so that you can eliminate these kinds of issues.

Step 2:-

There is no question that halogen bulbs become very hot. So, when you feel the need to replace and touch them with your hands, they become very dirty. Bulbs need an evenly heated surface so that they can last for a longer time. The best practice is to use latex gloves and try to touch the metal (or plastic) base while installing them. However, this can be tricky because of the limited amount of space.

Step 3:-

Cheaper bulbs are nowhere near the standard high-end bulbs. The filaments on the bulb are made from a very thin tungsten gauge, which might fail in no time if the quality is not good. Vibrations are the common causes that make these cheaper bulbs fail. If household technologies are put into the car bulb, there will be failures. Therefore, look out for a high-quality brand that specializes in car bulbs.

Step 4:-

If the excessive vibration is causing the problem then, Therefore, check the retaining springs that hold the bulb and double-check whether they are tight and secured.

Hence, these are some basic steps through which you can avoid such incidents which kept you wondering, “why does the same headlight keep burning out?


1. How long should headlights last?

Most halogen headlights will generally last you a couple of years without issue! However, this of course is determined by how much you keep those headlights on. That said, LED headlights realistically will last as long as the car, and probably past that, as they don’t have filaments like halogen bulbs.

2. Will Autozone change my headlight?

Autozone is actually one of the great stores where you can stop by, buy a bulb, and get a bit of help installing them! That said, if you have a vehicle where it requires quite a bit of work to install bulbs (looking at you Gen 1 Audit TT), you likely won’t be able to get much help, and will have to find a qualified mechanic.

3. Should I replace both headlight bulbs at the same time?

Replacing both bulbs at the same time is not really necessary, and you can do one at a time. However, you generally should change both, if you are changing types of bulbs, as the colors will be slightly different.


We hope the above-mentioned information which kept you wondering, “why does the same headlight keep burning out?” will be helpful to all the readers. If anybody’s doubts persist feel free to comment in the comment section below. We’ll definitely try to solve your doubts as soon as possible.

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