How to Remove Moisture from Headlights

Missing headlight bulbs and dirty headlight casing can dramatically reduce your nighttime vision. However, sometimes the issue is caused by moisture trapped within your headlight assembly. If you’re wondering how to get moisture out of headlights, here are a few helpful tips and tricks to help you restore your full headlight field of vision.

How Moisture Affects Your Headlights

Removing a headlight bulb from a headlight casing placed on the fascia
Removing a Headlight Bulb

Trapped moisture can be dangerous, particularly for nighttime driving. Just like debris and fog on the exterior of your headlight casing, moisture trapped inside the seal can dim your lights or even create blind spots.

In some states, you won’t pass your vehicle inspection with headlight fog. This could be caused by a leak in the seal around your headlight, which allows water to enter the space behind your headlight lens. Alternatively, it may be caused by moist air, which heats up when your headlight bulb is turned on and cools off when it is shut off. This causes condensation to form on the inside of the lens.

Here are some steps you can take to remove moisture from your headlights:

1. Remove Minor Condensation

If you notice a small area of condensation building up in your headlight, there’s a few easy tricks you can use without breaking the headlight seal. Breaking the seal between your headlight lens and housing is relatively easy, but once it’s broken, you’ll need to be very cautious to create a firm seal once you replace it. If you aren’t comfortable working with sealants, it might be worth bringing your car to a mechanic who is.

Before removing the seal, check your headlight housing vent. The exact location of the venting will depend on your make and model of vehicle, but most headlight units have a vent to help prevent condensation buildup. A common cause of minor condensation is a blocked vent. This could be caused by debris, spider webs or dust. Carefully wipe the vent or blow it out with compressed air. Try not to blow or push any debris into the headlight housing, otherwise you’ll need to break the seal to remove it.

2. Remove Major Condensation

Major condensation requires more extensive tricks. There are a number you can try, depending on your resources, available time and the amount of condensation. For major condensation removal, you’ll need to remove the headlight unit. Refer to a service manual for instructions on removing the bulb, electronics, plugs, and any other components you can. Carefully remove the headlight housing and follow the removal strategy.

Use a hairdryer to dry out the moist air without breaking the seal. Use a hairdryer to blow hot, dry air into the vent or on the outside of the headlight unit. As it heats up, it should dry out. Wait for your headlight unit to cool off to determine whether this strategy was effective.

Finally, if you want to know how to get water out of headlights thoroughly, you’ll need to remove the seal. Before attempting this, check a service manual to figure out how to remove your seal. This route will be substantially more complicated and require a heat gun unless your assembly uses a replaceable seal. If you don’t have experience using a heat gun in these kinds of situations, your headlight assembly is probably not the thing to try it out on. These instructions assume you have a replaceable seal.

For this removal strategy, you’ll need hand tools like sockets and screwdrivers, silica gel packs, a lint-free cloth, and a sealant. It’s more time consuming than other options but should thoroughly remove any moisture buildup.

Carefully remove the seal and the clear plastic headlight cover from the housing. Make sure you don’t miss a screw or other attachment point. Wipe off the existing moisture with your cloth. Be sure the cloth is clean and dry before use. Drying off the interior with a cloth will remove most of the moisture, but it isn’t a perfect solution.

In order to soak up the remaining moisture, use silica gel packs. These can be placed in the headlight assembly and are designed to soak up any moisture in the air. You don’t want a pack bouncing around in front of your headlight beam, so be sure they aren’t blocking the light or exposed to the bulbs.

Check again to see if there’s any existing moisture or debris in your headlight assembly. Use the following steps to prevent further moisture and effectively reseal your assembly. This is the most important step, as improper reinstallation will allow more moisture to enter your headlight.

3. Prevent Further Moisture

The key to preventing further moisture is creating a strong seal. There’s a number of products that can help you recreate a firm seal. First, inspect the seal for any damage or debris. If necessary, run a bead of silicone sealant around the factory seal area to ensure no moisture can enter the assembly, or replace the seal if your housing uses a replaceable seal. You’ll also want to check the O-rings that protect the electrical connectors, bulb, vent and other components of your headlight assembly.

Consider purchasing a few quality products to promote a strong seal. Silicone spray is excellent for protecting your O-rings, and silicone sealant gel can be used to repair any cracks or damaged portion of seal between the lens and housing.

After you’ve carefully inspected and sealed your headlight, it’s time to reinstall it. Check that you have the correct angle and that all brackets and electrical connectors are firmly in place. Test out your light to be sure it’s working properly and shining brightly. Routinely inspect your headlight for any signs that it may not have sealed properly.

Find All the Parts You Need

Restoring your headlight may be a time-consuming project, but with just a few tools and these steps you can avoid a costly headlight assembly replacement. If you need to remove moisture from one headlight, keep an eye on the other one as well. Chances are, the same issue may appear on your other headlight.

Some issues can’t be fixed easily by wiping them with a cloth or drying them out. If your headlight is severely damaged or still collects moisture, it may be time for a car headlight assembly replacement. Learn more about your replacement options at AutoZone. Talk to a friendly and qualified professional who will assist you with any questions about silicone sprays, headlight replacements and other car maintenance needs. Restore your vehicle and drive safely, day or night.

Advice, how-to guides, and car care information featured on and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

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