Top 6 Reasons why you headlights keep Burning Out

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Headlights can’t last forever. If you frequently replace your car’s headlight, there might be an underlying problem that is responsible for their short lifespan. A few reasons could be a loose connection, poor quality of bulbs, and excessive condensation.

So why do your headlights 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.

These two major reasons are going to be about 75% of the issues you are running into, however there are of course others! Keep reading to learn more about this, and the rest of the possible reasons.

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.

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.

It is a good idea to fit new connectors to the bulb (like these) so that you can eliminate these kinds of issues. Therefore, if you find out that the connectors are burnt and showing signs of corrosion, you should replace them.

2. Contacting the bulb with your fingers while installing

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.

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 on the bulbs and they explode.

Best practice is to use latex gloves like these and try to touch the metal (or plastic) base while installing them. However, this can be tricky because of the limited amount of space.

3. Poor quality of the bulbs

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.

Also, the poor quality of the tungsten gauge can fail especially if there is an uneven flow of voltage on the regulator. 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. I personally really like this brand right here, as it last a while and is rather bright!

Alternatively, adapting your car over to LED light bulbs are a great solution. LED bulbs last longer, and give better visibility! We recently purchased a set like these, and they have been great.

4. Excessive vibration

The halogen filaments inside the bulbs can’t withstand excessive vibration. Therefore, check the retaining springs that hold the bulb and double-check whether they are tight and secured. Also, it is good to check the suspension springs, wheel bearings, and wheel balance so that they don’t cause major vibrations.

5. Condensation inside the headlights

One thing a lot of people run into, is additional condensation (which can actually be solved). 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. Headlights are made in a way so that there is proper ventilation from all sides.

These ventilation holes are designed to allow a certain amount of airflow and keep the lens free of moisture. Sometimes, the headlight cover on the back is not mounted properly or the sealing might have broken. This can lead to excessive condensation.

Also, a potential water leakage to the housing might result in excessive condensation. This could be due to heavy rainfall.

6. 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.

Frequently Asked Questions

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.

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.

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.


So, those were the reasons why your car’s headlight keeps on burning out. Watch out for the signs and regularly check them when you are visiting for your car servicing.

I would highly recommend getting yourself a high quality bulb, and keep an eye out for accidentally touching the bulb during install. You should be all set after that!

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