Why do headlights get foggy?

Headlights steam up for the same reason windows steam up: everyone knows what condensation is, and no one cares when it's there! Windows fog up when the outside temperature is lower than the inside temperature, usually during the coldest and wettest times of the year. The same thing happens with headlights: as a result of climatic conditions, a layer of mist forms inside the optics, which is responsible for fogging. Unfortunately, turning on the heater or air conditioning isn't enough to get rid of the mist, as it is with windows.

In fact, there's a similar system for headlights, but it's not quite as effective. The heat emitted by headlight bulbs has a defrosting effect similar to that of hot air from a fan, so driving with the headlights on helps prevent condensation. However, modern light sources produce less heat than halogen and incandescent bulbs: xenon headlamps actually tend to fog up more than halogen headlamps.

Paradoxically, it is the most advanced headlights - LEDs - that are most affected by this phenomenon, as modern light sources do not emit heat.

Why should you repair it?

There are several simple reasons:

• The efficiency of the lighting decreases several times, if you like, it can be compared to a dirty headlight... This is dangerous in itself, because you may not be able to see the pedestrian crossing the street.
• Fogging is often accompanied by the accumulation of water inside the headlight, which corrodes and destroys all the metal parts of the headlight. Although many manufacturers now use plastic, the lamp itself is made of glass and metal.
• If moisture gets into a heated lamp, it can simply shatter.
• Water is a good conductor and can short out the lamp contacts. The less it burns, the more the fuses will blow, and if this happens on the road, you may find yourself without street lighting.
• Lamps burn out more often, again due to moisture getting into the contacts.

Generally, problems are insured, so something has to be done. The reasons are often the same.

What causes foggy headlights?

Cause 1: Faulty rubber seals.

At the junction of the glass and the optical housing, elastic seals are installed in the factory to prevent moisture from entering the headlamps. If they are cracked or some of the rubber is worn out, simply replace them.

Cause 2: Ventilation holes are clogged

If the seals on the car's headlights are intact, pay attention to the ventilation holes. Sometimes they can become clogged with dirt, such as leaves. Since the moisture that enters the housing is not removed naturally, it condenses on the glass.

Cause 3: Cabinet cover has cracks

Check the case cover. If there are cracks, it is easier for moisture not only to change, but also to enter the lens cavity. Such a defect can be easily corrected by replacing the broken part.

Cause 4: The projector cabinet is overheated

When a powerful lamp is installed in the projector, the projector cabinet may overheat. As a result of melting, holes may appear, allowing moisture to enter more easily. If this happens, the entire lamp must be replaced.

When replacing the projector, remember to do this with the lamp cold. If you touch a hot object with a cold one (a small drop is enough), it may burst.

Cause 5 Water inside the projector

Water can also get into the projector when washing an engine or car. Therefore, the jet should not be directed at right angles to the headlights themselves. And if you use a touchless washer, make sure the bell of the station is no less than 30 centimeters from the headlight.

Cause 6: Damage to the headlights

This happens in an accident, for example, you didn't break it, but you pushed it a little. The plastic or glass can pull away from the housing, creating a "fistula" that also draws in outside air and water.

Cause 7: Failure of the hydrocorrector

This is not a specific cause, but it is possible. The fact is that some headlights have a hydraulic corrector inside. In other words, you turn the knob on the dashboard, the pressure increases and the light level increases or decreases according to your needs. But this happens a lot - rarely, but it happens.

So what do you do?

You know, many people save money and in case of an accident they put non-original spare parts in your car. Lights are no exception, because often the price of the original is simply out of reach. When it starts to sweat, but there's no external damage.

What to do if it looks normal, there are no chips or cracks, but moisture appears from the inside?

• You need to dry the headlight - this is a must, otherwise the moisture inside will cause it to evaporate. If you can't remove it from the body, you can try drying it with a hairdryer, for example - the air is hot, so it evaporates the moisture.
• After drying, it's a good idea to seal all the joints between the glass and the case - this is done with a putty, preferably colorless. This will remove any small cracks.
• Check the fit of the bulb to the housing. It should have a seal, sometimes rubber, sometimes plastic. If it doesn't, this is where the moist air can be sucked in.
• In order to make an accurate determination, it is advisable to remove the headlight. There is a 100% method to determine the "fistula". We pour water into the bathroom - then simply lower the headlight into the water - and observe. If there are bubbles, that's our air leak location. We mark it, then we seal it. Again, use a sealer. When it dries, you have to repeat the process.
• If the glass is cracked. This is more problematic - ideally you should replace the glass, but it's not always sold separately, and buying a whole headlight is not an option. So what can you do? If you have a small crack, you can put a tinted film over it - just don't get a dark film, get a clear one. It has an adhesive base that will seal any "holes" and the glass will no longer creep.
• If the crack is large, a replacement is advisable. By the way, many people look for originals when analyzing, this is a way out, just take something that is not too worn, otherwise it will be necessary. You can glue it, but remember that it has to be airtight.

Very important: If you remove the parts yourself to fix the dampness in the headlights, you'll have to adjust the lights properly afterwards. This is because removing the headlights will cause them to become misaligned, and it is generally not possible to drive safely without readjusting them.