How To Get Water Out Of Headlight

This is our guide on how to get water out of a headlight. 

Water and moisture can build up in a headlight over time. This reduces visibility and also ruins the look of your vehicle. 

But it’s fairly easy and quick to get water out of a headlight. And you only need a couple supplies that you might already have lying around the house. So, you don’t have to go pay someone or go through the hassle of taking your vehicle to the shop. 

We’ve been testing and working on headlights for over a decade. So if you needed help figuring out how to get water out of a headlight, you came to the right place. 

Keep reading for more information on how to get water out of headlights. 

What Causes Water To Build Up In Headlights 

A bit of water in your car’s headlight assembly is nothing to be concerned about. Almost all car’s experience this at some point. 

When you run your car’s headlights for a while, they get very hot. The headlight assembly is designed to effectively evacuate this heat via small vents in the headlight that let fresh air in. 

But if the outside air is very humid, it contains a lot of moisture in the form of water vapor. This water comes into the headlight assembly and since the outside surface of the headlight is colder, the water condenses on the inside. 

Water in the headlight can cause light to be diffracted abnormally, and reduces the amount of light that is generated. This causes lower visibility, which is the last thing you want for nighttime driving. 

What You’ll Need To Get Water Out Of A Headlight

Here’s what you need to get water out of a headlight. You probably have most of this stuff lying around the house, and if you don’t, you can easily find it at a local store or online. 

Vacuum Cleaner

The vacuum cleaner will be used to suck out the moist air and water from the headlight assembly.

Hose Pipe

You need a few feet of hose pipe, such as the one used to drain dehumidifier units. Again, you might already have this, and even if you don’t, you only need 4 or 5 feet, which shouldn’t be too pricey.

Duct Tape

We use duct tape to ensure that the hose pipe seals with the vacuum cleaner properly. 

Hair Dryer

A hair dryer will be used to pump in fresh air from the outside to replace the moisture and humidity inside the headlight assembly. 

How To Get Water Out Of Headlights

Here is a step-by-step guide on how to get water out of a headlight. 

Step 1: Remove The Bulb From The Headlight Assembly

The method we use here does not require you to remove or take apart the entire headlight assembly. However, you will need access to the inside of the assembly. And to that end, you will need to remove the headlight bulb from its socket so that there’s space for the hose to go inside. 

The process for removing the headlight bulb will differ from vehicle to vehicle, so be sure to consult the owner’s manual of your car for tips on how to remove the headlight bulb.

Step 2: Connect The Hose Pipe To The Vacuum Cleaner

Now, connect one end of the hose to your vacuum cleaner. To make this easier, try to use the vacuum attachment that has the smallest opening. Additionally, we recommend using duct tape to make sure there are no gaps between the hose and vacuum cleaner nozzle. 

Step 3: Route The Hose Inside The Assembly

Now, put the other end of the hose pipe into the headlight assembly, via the empty headlight bulb socket. 

Be sure to put the hose far enough inside the assembly that it can suck all of the moisture out. 

Step 4: Position The Hair Dryer Next To The Headlight Assembly’s Vents

The vacuum will remove the moist air and water from the headlight assembly. But we also need to replace this air with fresh air from the outside so that we get better circulation and faster water removal. 

We’ll be using the dryer for this. Find the vents in your headlight assembly and place the hair dryer such that the nozzle is pointing directly inside the headlight assembly. Here, you might have to take off a small rubber boot to get access to the vent. 

Step 5: Turn On The Vacuum Cleaner And The Hair Dryer

Next, turn on the vacuum and the hair dryer. Keep the speed low at first and check if the moisture starts dissipating. If not, crank up the haro dryer and the vacuum. Now, the water and moist air evacuated by the vacuum will be replaced by fresh air being sucked in by the hair dryer. 

As for how long the process should take, it depends on the amount of water in the headlight, the weather, and how fast you run the hair dryer and vacuum. 

In most cases, it shouldn’t take longer than 10 or 20 minutes for the water to be removed from the headlight completely. If it’s taking too long or if you haven’t noticed any improvement, try increasing the speed. 

Once all of the water has been cleared out of the headlight, replace the bulb and you’re done!

How To Prevent Water Build-Up In Headlights

The headlights on modern cars have unique designs that prevent water and moisture from building up inside the assembly, so this shouldn’t be that big a problem. 

The vents are sealed with rubber boots that prevent moisture from building up inside the headlight. 

So if you notice a lot of moisture build up in the headlight assembly, it’s probably due to the vents not sealing properly. It might even point to the vents being blocked by road grime, mouse droppings, or dead insects. 

If you want to prevent water from getting in the headlights, make sure the vents are not blocked and that the rubber boots are sealing properly. 

Another common issue that causes water to get into the assembly is a damaged headlight. This could be in the form of a cracked lens, or a loose seal somewhere in the headlight. 

This will be a bit trickier to fix, and in some cases, if the damage is extensive enough, you might even have to replace the headlight altogether. 

To prevent this type of damage, you could outfit your headlights with a polycarbonate protector or a plastic sheet that prevents small rocks and stones from making cracks in the headlight. 


In summation, it is pretty easy for water to get into your headlights. Thankfully, the solution is pretty easy and you don’t even need any special tools or supplies. 

At the same time, it is important to address the problems that cause water to get into the headlight so that it doesn’t happen again. 

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Richard Nickleson is the author and owner behind Headlight Reviews. He first started the site as a hobby to share his insights on car parts and specifically headlight bulbs, but it soon ballooned and now he writes on all topics surrounding headlights bulbs. If you've got a bulb question, contact Richard here.