Headlight condensation isn't ugly, it's unsafe!

Headlight Condensation: How to Fix Foggy Night Vision

Headlight condensation can be dangerous because it reduces visibility, and many states will not pass a vehicle inspection for a vehicle with fogged headlights. To improve night-driving visibility and the appearance of your ride, you need to get rid of headlight condensation.

If a headlight lens is cracked or a seal is broken or missing, water can leak in; you could have a puddle instead of just condensation. Even an undamaged headlight can develop condensation simply because of the natural heating and cooling of the bulbs. Driving on a humid night, for example, will heat up the air in the headlight housing, the moisture from the air will then condense on the inside when it cools off.

To start, remove the headlight unit from the vehicle. This generally requires no more than a repair manual or intuition and some basic hand tools. Note that these same steps apply if you find condensation in your taillights.

1. Get Moisture Out of Headlights

From the headlight unit, use regular hand tools to remove anything that you can, such as any bulbs, plugs, electronics and vents. Do not attempt to break the seal between the lens (usually clear plastic) and the housing (usually black, white or gray plastic), unless you are prepared to reseal everything, which can be particularly complicated and time consuming.

Depending on the level of condensation, you can go in a couple of directions to clear it out. If the condensation is minor, then a bit of compressed air or a couple of desiccant packets can get rid of any moisture in the housing. If there is a lot of condensation, then you can use a hair dryer or even an oven to dry out the headlight housing. Use low heat of less than 180 degrees Fahrenheit to bake the moisture right out of the headlight.

2. Prevent Future Headlight Condensation

Once the headlight housing is completely dry, you’ll want to prevent it from happening again so you don’t have to repeat this whole process again in a week. On the modern headlight unit, there are usually a number of rubber seals, such as those sealing electronics, the bulb cover or O-ring, and the vents — not to mention sealant between the lens and the housing. Do a complete inspection of these components to see if you can identify where water might enter or where air might not be able to escape. Use silicone sealant to keep moisture out of your headlights.

Spiders are notorious for building their nests in the darnedest of places, and headlight vents seem to be one of their favorites. Use compressed air to blow obstructions out of the vents. Be careful you don’t blow debris into the headlight housing; it may be difficult to blow it out again.

Make sure that any O-rings or seals are in good condition, replacing them if necessary. Use a little silicone spray to prevent them from splitting or shearing on installation. If you suspect the seal between the lens and the housing as the culprit, or you find a crack, then you can use clear silicone to seal it. Depending on the condition of the headlight unit, it may be more time effective to simply replace the whole unit.

Once you’ve finished drying out the headlight unit and making any repairs, or have simply bought a new unit, be sure to follow all instructions on installation, plug in all electrical connectors and test that everything works properly again.

For more information on headlight condensation, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo courtesy of Flickr

about author

Benjamin Jerew

Ben has been taking things apart since he was 5, and putting them back together again since he was 8. After dabbling in DIY repairs at home and on the farm, he found his calling in the CGCC Automobile Repair program. After he held his ASE CMAT for 10 years, Ben decided he needed a change. Now, he writes on automotive topics across the web and around the world, including new automotive technology, transportation legislation, emissions, fuel economy and auto repair.

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