How to Make Your Headlights Brighter & Troubleshoot Why They’re Dim

Have you ever been driven your vehicle at night and wondered, “why my car headlights are not bright enough?” Low headlight power can be an unsafe condition that can increase your chances of an accident. Here’s why your headlights may be dim and the proven steps you can take to brighten them. 

Why Are My Headlights So Dim?

There may be a number of reasons why your headlights may be dim. Here are the most common reasons for dim headlights. 

Yellow or cloudy lens

Over time your headlights may become yellow or cloudy. There are four possible reasons for this condition. First, your headlights may be experiencing oxidation due to microscopic cracks in the lens. The second reason could be due to road damage that can have caused pits and cracks on the lens. Another reason for yellow or cloudy lenses could be the accumulation of dirt or chemicals on the lens. Finally, a yellow or cloudy lens can be caused by water vapor inside the lens box.

Over time, the chances of a yellow or cloudy lens can increase. Therefore, you will want to check the condition of your headlight lens about once every couple of months. 

Bulb burned out

Another reason that your lens may not be bright enough could be due to a burnt-out bulb. On average, a headlight bulb will last about 500 to 1,000 hours. Therefore, if you drive your vehicle for about one hour per day, then you can expect to replace your headlight bulb about every 1.5 to 3 years. 


There are cases where your headlight bulb may simply be misaligned. A misaligned bulb will lead to a reduction in overall illumination out of the lens. So what are the causes of a misaligned headlight bulb? One of the main reasons for a misaligned bulb is damage to the internal components of a headlight. Another reason for misaligned bulbs is damaged lens. In these cases, a simple repair to the headlight component can bring the bulb back into alignment. 

Low lumen bulb

It is also possible that your headlight may have a low lumen bulb. If this is the case, then your headlight simply need a more powerful bulb to provide the proper amount of illumination. Typically, a headlight will need a bulb that with at least 2,000 to 4,000 lumens. This is the minimal amount of lumen power required in most states. 

Bad alternator

Do you notice that your headlights illumination changes when your vehicle’s engine revs? That means that your vehicle’s dim headlights are caused by a bad or a faulty alternator. In this case, you may have to repair or replace the alternator. There are some cases, where the issue may simply be a lose alternator belt. 

Not enough light in different zones

Finally, your headlight may not be providing enough illumination in different zones. For instance, you may not enough light to have a wide angle view at night. Perhaps your headlights can not allow you to see the road from a long distance. In these cases, you may want to investigate for any damage to the headlight lens or simply replace the bulb. 

How to Make Your Headlights Brighter

It is important to give yourself the proper amount of visibility when driving in low light or completely dark conditions. Here is a look at the common was that you can make your headlights brighter. 

Clean or restore your headlight clarity

You can clean and restore your headlights to regain brightness. If you are looking to clean your headlights, consider using toothpaste or baking soda as cleaning agents. Both toothpaste and baking soda are abrasive enough to remove the fogginess from your headlight without causing any permanent damage. 

Check headlight alignment

Be sure to check your headlight alignment. If you have a newer model vehicle, you can use built-in bubble levels that can help you align the vertical and horizontal setting of the headlight. If your vehicle doesn’t have a built-in bubble, then park your vehicle about six feet from a wall and turn on your headlights. Mark the location of the lights. From there, adjust the headlights until the light is pointed directly in front of the vehicle. 

Upgrade your bulbs 

If it has been more than four years since you have changed your headlight bulbs, then it is time to upgrade them. Be sure that you get bulbs that meet your state’s minimum required illumination. Typically, you will be looking for headlight bulbs between 2,000 and 4,000 lumens. 

Retrofit HID or upgraded lights

If you have an older vehicle, then you may want to consider retrofitting or upgrade the entire headlight unit. You can order HID kits online, or you can find them at your local auto parts store. These kits are easy enough for you to install on your own. You also have the option to have these kits installed professionally. 

Get supplemental lights to fill zones 

Finally, you will want to consider getting supplemental lights to fill in the dim zones on your vehicle. Some of the most effective supplemental lights include fog lights, a light bar and spotlights. Be sure to check your state’s regulations to see which supplemental lights are allowed. 

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