Why do headlights fog up from the inside?

The headlight is sweating, what should I do? A phenomenon from within. Step-by-step instruction

Spring and autumn bring a lot of moisture to the streets of our cities, sometimes puddles look like rivers. In such weather, everything and everyone fogs up, especially the windows inside the car. But often the headlights sweat too! That is, you turn on the light, and you can see fogging from inside. I want to say right away that this phenomenon is wrong, it needs to be eliminated...

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It can appear both on completely new cars and on those restored after an accident, for example. There are times when everything was fine, and then “bang” and I started sweating. Why? What to do? Let's figure it out, but first I suggest we talk about why this is so dangerous.

Why should it be eliminated?

It's simple, and there are several reasons for this:

The efficiency of lighting drops significantly; if you like, it can be compared to a dirty headlight. Which is already dangerous, because you simply may not see the crossing pedestrian.

Fogging is often accompanied by the accumulation of water inside the headlight, which leads to corrosion and destruction of all metal parts of the headlight. Although now many manufacturers are made of plastic, the lamp itself is made of glass and metal.
If moisture gets on a heated lamp, it may simply burst.
Water is a good conductor; it can short-circuit the lamp contacts. At a minimum, it will burn out, at a maximum, the fuses will blow out, and if this happens on the road, you risk being left without road lighting.
The lamps will burn out more often, again due to moisture getting on the contacts.

In general, problems are guaranteed, so something needs to be done. Often the reasons are trivial.

Causes of headlight fogging

To be honest, our company car had this problem. The headlight constantly fogged up, moisture collected inside, and then the light bulbs burned. This happened when a small pebble hit the headlight, let's take a closer look:

Incorrect design. Initially, the headlight must be sealed, that is, a closed air space is formed inside. If the headlight is not made correctly, then it will “capture” external air (or moisture) from the street, and if it is humid weather, then you will get fogging. The outside air will simply be humid, and it will condense on the glass of the headlight from the inside. The first Chinese cars suffered from this, the build quality left much to be desired, the headlight simply “blew” - hence the fogging. Now, of course, the problem has been eliminated, but the first cars suffered from such shortcomings.
Damage to the headlight. This happens during an accident, for example, you didn’t break it, but pressed it a little. Plastic or glass may move away from the body, and a “fistula” will appear, which will also draw in outside air and water.
Microcrack on glass. Again from this story, the glass cracks, the seal is broken - “hello” fogging.

Failure of the hydraulic corrector. A specific reason, but quite possible. The thing is that inside some headlights there are hydraulic correctors. That is, you turn the knob on the dashboard, the pressure increases and the light level rises or falls as you need. But often, especially on our VAZs, they break down, liquid leaks into the headlight and then fogs up. It happens - rarely, but it happens.

These are the main reasons, for example, in our working VAZ we had a problem with a microcrack, which was not visible, but moist air was drawn in through it and fogging appeared.

What to do?

You know, many people save money, and in case of accidents, they put non-original spare parts on their car. Lighting devices are no exception here, because often the price of the original is simply off the charts. If you start to sweat, but there is no external damage. This means a low-quality “Chinese” craft, either look for a place where moisture and air are drawn in, or replace it with a new original one (or better quality).

What to do when it looks normal, there seem to be no chips or cracks, but moisture appears from the inside?

There are several recommendations here:

It is necessary to dry the headlight - this is mandatory, otherwise the moisture inside will provoke evaporation. If you don’t remove it from the body, you can try drying it with a hairdryer, the hot air will evaporate the moisture.
After drying, it is worth sealing all the joints of the glass and the body - this is done with a sealant, preferably colorless. This way you can remove all small cracks.
We look at the fit of the light bulb to the body. It must have a gasket, sometimes rubber, sometimes plastic. If it is not there, it is through this place that moist air can be drawn in.
For an accurate determination, it is advisable to remove the headlight. There is a 100% method for determining a “fistula”. We pour water into the bathtub - then simply lower the headlight into the water - observe. If bubbles appear, then this is our place for air leaks. We mark it, then seal it. Again we apply sealant. After it has dried, you need to repeat the procedure.

If the glass is cracked. This is more problematic - ideally, you need to replace the glass, but it is not always sold separately, and buying the entire headlight is also not an option. What to do then? If there is a small crack, you can stick a tint film on top - just take a transparent one, not a dark one. It has an adhesive base that will seal all the “holes”, and the glass will not spread further.
If the crack is large, then replacement is advisable. By the way, many people are looking for originals in the analysis, this is the way out, just take one that is not too worn out, otherwise you will need to polish the glass . You can, of course, seal it, just remember it must be airtight. A short video to help.

That’s actually all the main causes and consequences, I think the information was useful to you. Read our AUTOBLOG.

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The headlight is foggy: 5 easy ways to get rid of moisture without removing the headlight

Foggy headlights are a serious problem. Headlights can sweat even on new cars, and there are several reasons for this. Ignoring the problem can affect not only additional costs, but also ride comfort. So how to fix this problem? Find out from this article.

To properly troubleshoot the problem, you need to know the reasons for the appearance of water in the headlights. The reasons may be the following:

Clogged hole in the ventilation system. There are two breathers inside the headlights through which air is ventilated. The hole may become clogged with debris from under the hood or during repairs, which is very rare.
The light bulb was replaced incorrectly. Everything is simple here. The little paw stands crookedly in its hole.
Cracks appeared in the glass. This can happen due to an accident or improper installation of the structure. Through the gap, moisture will always get inside the headlight.
The sealant has dried out. Sealant tends to dry out over time. Depressurization can also occur due to an accident.
Defective headlights. Cases are very rare. The glass may be crooked or have incorrect geometry.
The hydraulic corrector is broken. Failure of the device results in leakage of liquid, which can get inside the headlight.

How to eliminate fogging at home

You can begin to solve the problem yourself after the exact cause has been established. It is impossible to detect microcracks in plastic with the naked eye. In this case, the headlight will sweat over its entire surface, and not in any specific place.

To check the device you need to:

Remove the terminals from the battery;
Unscrew the light bulbs;
Clean the body;
Check for cracks in the seams.

If the headlight fogs up due to cracks in the seams, it is necessary to clean the surface of the old glue. Next, dry the headlight and degrease the surface. We seal the headlights with sealants. A silicone-based mixture is best.

To check the plastic for microcracks, it is immersed in water. The presence of cracks reveals air bubbles. A colorless sealant will help correct the situation. Another way to repair a crack is to seal it with instant glue.

The breather is clogged, what should I do?

The check valve design is not the same everywhere. But the operating principle is identical. Sometimes the valve may not close and remain in the open position. Air enters through this hole and causes condensation to form. Of course, you can replace the part, but you can do it differently.

Place a small bag of silica gel inside the headlight. These balls absorb moisture. It is important to place the bag in a suitable place. It should not be placed near a light bulb. It won't be able to burn, but it will melt. One sachet is enough for about autumn-winter.

You can dry the accumulated condensation with a hair dryer. This must be done carefully, otherwise under the influence of high temperature, the plastic may become deformed. Try to constantly move the hair dryer and not hold it too close. The good thing about this method is that you don’t need to remove the headlight from the car.

The problem can also be solved as follows; remove the seal cap from the headlight and drive like this for a while. The engine temperature will evaporate the condensation. Then close the seal cap tightly. There is a risk of dust and other debris from driving on dirt roads. So try to avoid this.

You can create additional ventilation by drilling a small hole at the bottom of the headlight. Sometimes, factory ventilation is not enough, and therefore additional holes are made. It often happens that the hole aggravates the situation. Then you can simply seal it.

Removing condensation from a headlight is not so difficult. You will have to tinker, but it will take a little time.

Do you have any questions or something to add about the article? Write in the comments, perhaps this will greatly help readers in the future. Also subscribe to our channel in ZEN.

The headlight is sweating

The main reason why a headlight sweats is the formation of condensation on the inner surface of its glass. In turn, it is formed as a result of the temperature difference (heating) of the headlight due to the operation of the lamps and its subsequent cooling. To regulate the pressure inside the headlight (simply speaking, so that it does not burst), there are special control valves on its body. And it is precisely the violation of the tightness of the glass, seals or ventilation valves that is the main reason why the car headlight sweats, both front and rear.

All car headlights “breathe”, so slight fogging of the headlights from the inside is a common physical phenomenon and is not a defect ! If condensation disappears 30 minutes after turning on the lamps is no need to deal with it .

Sometimes the increased ability of headlights to fog is a design feature, then in such headlights the manufacturer puts silica gel inside to absorb excess moisture. It is considered abnormal when the veil of dampness does not go away on its own after the headlight has been on for a long time or drops of water are visible inside. The main thing is that water does not collect there in large quantities!

How the headlight unit works

To find out the reason why car headlights sweat, you must first understand how the headlight is designed in general, and what elements are included in the design of its unit. At first glance, it may seem that its internal volume is completely sealed from the surrounding space in order to protect the lamp and reflector from dust and moisture, but this is not so.

During operation of the lamp, the inner surface of the glass is heated by the heat emanating from the light source. Thus, there is a temperature difference between the inside and the outside surface. The heated air needs to find a way out. If the headlight were completely sealed, then, firstly, the internal pressure could simply damage the reflector and/or glass, and secondly, with a much colder external surface inside the headlight, moisture would begin to condense and settle on the glass.

To compare the pressure during heating and cooling of the air inside the headlight, automobile designers proposed the use of special ventilation valves - exhaust and supply. The first one releases hot air outside while the headlight is heating/operating, and the second one sucks in cold atmospheric air as the headlight cools down after it is turned off.

Why is fogging harmful?

Using a headlight that even sweats a little is actually not just harmful, but dangerous! After all, an ugly appearance is just the slightest bit of an unpleasant phenomenon and a reason to eliminate the reason why the headlights sweat from the inside. The following negative factors can result from the formation of condensate in its internal volume:

Deterioration of illumination . Even a small amount of condensation in a headlight can significantly reduce the light output from it. This occurs due to improper scattering of light at the points where it is refracted on drops of condensate. And if the car owner uses good car lamps paired with good optics, then this drawback is not so critical. If the lamps and headlights are of low quality, then the problem takes on a large scale, similar to a headlight that is very contaminated with road dirt or sand.
Reflector corrosion . Often, the reflectors of cars in the middle and lower price categories are coated with a low-quality coating, which over time can become covered with pockets of corrosion. Naturally, this will not only worsen the luminous flux, but also reduce the overall life of the headlight in the long term.
Lamp burnout . In particular, moisture can damage the electrical contacts of the lamp and the wiring in general. Because of this, firstly, the lamp may fail earlier, and secondly, the risk of a short circuit in the electrical circuit of the car increases.
Lamp rupture . If cold moisture gets on a heated lamp, its glass body may simply burst. This is especially true for lamps that heat up to significant temperatures, in particular halogen lamps.

Why do headlights sweat?

The factor behind the formation of glass fogging inside the lighting unit (headlight, taillight or foglight) is a temperature difference , which ensures air movement inward and moisture condensation from it. Cold air is sucked in after the light bulbs are turned off or when leaving a warm garage into the cold . The main reason why the headlights on a car constantly fog up is a violation of ventilation in its internal volume . In turn, such a situation can arise for four main reasons .

Clogged valves

As mentioned above, the exhaust and supply ventilation valves are designed to ensure normal air circulation inside the lighting fixture, as well as to equalize the temperature on the inner and outer surfaces of the glass. In spring, autumn and winter, when the air is especially humid, condensation can form even with fully functional valves! Especially in the first minutes after turning on the low beam. However, the moisture in such cases must evaporate within up to 30 minutes.

Accordingly, when the valves are clogged with dirt and/or dust, the natural ventilation of the headlight is disrupted, moisture does not evaporate and condensation falls from inside. In addition to contamination of the ventilation valves, mechanical damage to one or the other valve is possible, for example, after an impact. But this problem is relevant only for the front or rear headlights; if the fog lights sweat, then the following two reasons are possible.

Cracks in glass

Since the glass also seals the internal volume of the headlight, a violation of its integrity will naturally lead to moisture from the outside getting inside and accumulating there. In this case, it can not only condense on the inner surface of the glass, but also collect at the bottom of the headlamp unit.

Similar reasoning is valid for the headlight housing, although this happens less frequently. For example, a small crack may appear on the plastic, through which moisture will similarly enter. In old metal headlights, holes or microcracks may appear along areas of rust.

Destruction of seals

The glass of most car lighting fixtures is installed with special sealants for headlights. They are designed to ensure the tightness of the headlight unit. Please note that manufacturing plants typically use higher quality sealants than those available commercially. This is especially true for used cars and cars after repairs, in particular, with the replacement of a headlight and/or its glass. Similar sealants are also used as seals for headlight housings and connectors for electrical wiring harnesses.

Glass seals, housing covers, or wiring harnesses can dry out or become damaged over time. As a result, they lose their sealing properties. The glass and headlight housing are usually held together with sealant. The wiring harnesses coming from the rear of the headlight can be sealed with either sealant or a rubber seal. They have the same function. Depressurization can occur for natural reasons, that is, as a result of aging, or due to mechanical damage, for example, as a result of an impact or an accident.

On some cars (for example, on some KIA models, the headlights fog up even on a new car), the design provides for the use of a silica gel bag. It is used for additional moisture absorption, including in humid weather. On forums and reviews from car enthusiasts, you can often find stories that such silica gel actually works very poorly, and in order to eliminate the problem it must either be replaced or periodically dried.

Damage to the hydraulic corrector

On domestic VAZs and Ladas or old foreign cars, the reason that the headlight is sweating may be a broken hydraulic corrector - this is a device with which you can adjust the intensity of the light beam. The device is controlled by a knob on the control panel. When turned in one direction or the other, the liquid in it changes its pressure, and through a special mechanism the light intensity also changes. But sometimes (though rarely) the hydraulic corrector housing can burst and the liquid in it simply pours into the internal cavity of the headlight. This naturally leads to fogging of the glass and also disables the hydraulic corrector.

What determines the degree of fogging?

Having dealt with the reasons, let’s briefly look at what factors influence the degree of fogging of the headlight from the inside.

Type of lamp used

Different types of lamps (halogen, xenon, LED) emit different amounts of heat depending on the power consumption. Accordingly, the more they heat up the headlight, the greater the temperature difference and the higher the risk of condensation. Halogen light sources are considered the hottest. In second place are xenon ones, but they cannot be installed in all headlights. LED lamps are the coolest, but according to the Road Traffic Regulations they can only be installed in specially designed lighting fixtures.

Glass area

The wider (larger in area) the headlight, the greater the likelihood of fogging. This is due to the fact that condensation often remains on the edges of the headlamp (the upper areas away from the lamps), which does not heat up sufficiently and does not evaporate. Conversely, small (for example, round) headlights are less prone to fogging.

Seasonality and place of operation of the machine

In humid weather, the air is oversaturated with moisture, which can get inside the headlight. Often, even drying with low beam does not help. Similar reasoning is valid for certain territories, for example, located on the seashore with high humidity (for example, Primorye, Far Eastern regions).

After washing

Quite often, headlights sweat after washing. There are two possible options here. First, the headlight was washed with cold water when it was not yet cool enough. Secondly, the headlight seal is broken. In such conditions, if the car was washed with hot water and in conditions of steam and water spray, then small drops of water could themselves get inside the headlight. Or hot steam condensed on the inner surface of its glass.

How to fix foggy headlights

The most important question is what to do if the headlights sweat from the inside? There are two ways to correct this situation. This is either a repair aimed at improving the sealing of the glass, or the lamp seal, or using folk remedies.

People usually turn to a car service center for help if there is already a large amount of water in the headlight and it is almost impossible to dry it (the so-called “aquarium”). However, simpler methods are more often used. The first one is to simply dry it from the inside. In particular, turn on the low beam for 20...30 minutes. At the same time, it is advisable to remove the covers from the optics. And if the car is parked in a warm (heated) garage for several days, then you can simply remove the mentioned covers and leave it there to dry.

Or, as a quick drying option, dry it with a hairdryer or remove it and put it on the radiator. When using a hair dryer, you need to be careful not to melt the plastic elements. However, it is easier to use a standard car tire pump (compressor) and blow a stream of cold air over the headlight. Usually the procedure takes about 15...20 minutes.

If dismantling the headlight involves removing the bumper, it is easier to place a bag (like in new boots) with dry silica gel inside the headlight. It will absorb moisture. Then take it out, dry it, and use it again on an ongoing basis, periodically removing and drying the substance.

However, eliminating the phenomenon itself is an ineffective task; it is much more important to take care of correcting a specific defect: seal the perimeter with sealant, replace the cracked part (or solder it if it is the rear plastic part of the headlight), clean the ventilation valve or seal the entry point of the lamp or its wires.

When the headlights sweat from the inside, what should you do first?

After moisture has been removed from the headlight, the first thing you need to do is find out why it got there. Inspect the glass for possible cracks. Even small chips can allow a small amount of moisture to pass through from outside.

Next, you should check the functionality of the exhaust and supply valves. On various designs of headlights (cars), they are either small plastic caps with foam inserts in the optics housing, or membranes with several holes. Even if the valves seem to be in working order at first glance, it is still better to clean them. It is also recommended to replace their foam rubber with a new material.

Next, you need to check the seal on the headlight cover, the integrity of its body and glass. If the reason for moisture penetration is the loss of its properties by the sealant, then after removing the drying headlight, you must reapply it. It is important to choose the type of sealant for the headlight. After application, you need to give it time for it to completely harden. The appropriate time is usually indicated directly on the packaging of the sealant.

It is imperative to check the location of the light bulb to the headlight housing. There is always a gasket in this place. It can be rubber or plastic. If it is not there, or it is leaking, then there is a high probability that cold air is leaking through this place, which leads to such consequences. You can buy a new gasket, make it yourself from scrap materials (taking into account the temperature of the heated lamp), or cover everything with sealant.

After such work, it is imperative to check the headlight for leaks. To do this, you can simply lower it, glass side down, into a container of water of a suitable size. Please note that in this case it is NOT possible to wet the breathers (drainage exhaust and supply valves), or rather their terminals!

Why do headlights sweat and how to fix it?

Why do headlights sweat?

Are you saying this is normal?

But it’s just splashing there! How so?

Is this probably dangerous?

How to remove moisture?

Well, I dried it, and then what?

How can you stop your headlights from sweating?

Lifehacker has collected the simplest and most effective ways to get rid of hated condensation.

Why do headlights sweat?

Due to condensation. Working lamps heat the air inside the headlight, and as the temperature rises, the pressure also increases. To prevent the optics from simply bursting, the headlight units are not completely sealed. The pressure is equalized by special valves at the top and bottom of the housing, through which air exchange occurs.

After turning off, the headlights begin to cool, the pressure in them decreases and air from the atmosphere is sucked in through the valve. In autumn and spring - when the air is cold and humid - condensation forms on the glass from inside the heated headlights.

Are you saying this is normal?

Yes, this is a natural process. Condensation disappears just as it appears. Most manufacturers do not consider fogging to be a defect in headlights and allow short-term moisture formation. It should disappear within 30 minutes after turning on the low beam.

But it’s just splashing there! How so?

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But this is already bad! If the moisture inside the optics does not evaporate, but flows down the glass and accumulates into entire puddles, turning the headlights into an aquarium, urgently look for the cause of the ventilation problem. There are three possible options.

Valve clogged. With prolonged use, they become clogged with dirt and dust, clogging the headlights. The air exchange of the internal cavity is disrupted. The moisture does not evaporate and condensation occurs.
Cracks in glass or case. Even through minor damage to the headlight units, water can get inside and accumulate there.
Destruction of seals. Glass, housing covers and wiring harness connectors have hermetically sealed seals that protect the headlights from dust and moisture. Over time or after an accident, the material partially collapses and does not perform its functions.

Is this probably dangerous?

Yes. There is nothing good about this. In addition to the unsightly appearance of headlights, fogging leads to yellowing and corrosion of reflectors, and deteriorates illumination due to the refraction of rays on condensate drops and improper dispersion of light.

In addition, moisture damages the electrical part of the optics. Lamps burn out prematurely, contacts oxidize, and the light may go out at the most inopportune moment. And, of course, the risk of a short circuit in the wiring increases.

How to remove moisture?

The headlights need to be dried. The easiest way is to remove the covers from the optics and turn on the low beam for a few minutes. In a heated garage and in warm weather, you can simply open the headlight housing and leave the car for a couple of days. You should not drive without covers, otherwise dust will get inside and you will also have to deal with dirt on the reflectors.

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Another option is to direct a stream of air with a compressor or hair dryer inside the headlight. In 15–20 minutes, all moisture should evaporate. The main thing is not to overdo it with the air temperature, so as not to melt the body and overheat the reflector or glass.

If the headlight is attached with two or three bolts or even with latches, then the easiest way is to remove it, take it home and dry it on a radiator or just in the room.

Well, I dried it, and then what?

Now you need to eliminate the cause of the fogging so that it doesn’t happen again. Check the drain valves on the housing. On different optics models, they can be in the form of simple plastic caps, curved tubes with foam inserts, or membranes with several holes. If necessary, clean the valves and replace the foam with new ones.

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Inspect the seals on the lid and make sure there are no cracks in the body or glass. It is worth fixing these problems yourself only if you are confident in your abilities. Often, removing headlights involves disassembling the bumper, and to restore the tightness of the joints, you need a special sealant and sealing tape.

How can you stop your headlights from sweating?

Silica gel packets are secured with double-sided tape. Photo accord-russia.ru

Yes, there are several tricks to prevent condensation from falling out.

If possible, turn off your headlights a few minutes before entering the car wash to allow them to cool.
Place a couple of bags of silica gel inside the headlight cover - it will absorb some of the moisture. Kia and other manufacturers install this upgrade from the factory.
Check drain valves regularly and clean them to keep your headlights from becoming clogged.

Foggy headlights - how to deal with it?

The formation of condensation inside headlights is a fairly common problem faced by car owners. If the lighting equipment is in good condition, slight fogging of the optics causes the working light bulb to come into contact with moisture. As a result of the temperature difference inside the headlamp, water droplets form on the inside of the glazing. Most often, such condensation appears during washing.

Since each headlight (block headlight) is equipped with a special ventilation and drainage system, moisture can get inside the optics through its channels. To quickly eliminate this condensation, just open the hood for 20-25 minutes. If fogging of the headlights is constant, this indicates a malfunction of the equipment.

Why do my headlights fog up?

The causes of fogging may be the following:

violation of the integrity of the headlight housing;
destruction of the sealant layer connecting the glazing to the body;
violation of the tightness in the places where the wiring is supplied to the light bulbs;
microcracks in headlight glazing;
clogging of ventilation ducts and holes that provide air circulation in the headlight;

One way or another, all of the above malfunctions lead to a violation of the headlight seal. Depending on the specific source of condensation inside the optics, there are various ways to eliminate fogging from the headlight.

Consequences of optics fogging from the inside

The constant presence of condensation inside the headlight creates a lens effect, which leads to refraction and scattering of the rays. As a result, the lighting efficiency is sharply reduced, which makes driving more difficult.
The presence of moisture negatively affects the contacts, significant oxidation of which can cause failure of the electrical wiring.
Moisture falling on the heated surface of the reflector leads to its destruction.
The presence of condensation on a metal surface leads to corrosion. In turn, sooner or later, rust can lead to a loss of functionality of the metal parts of the headlight.
High humidity significantly reduces the service life of lamps.

If a headlight fogs up, only an experienced specialist can tell you exactly what to do. After all, this requires certain knowledge, skills and equipment. For example, it is almost impossible to detect microcracks in the glazing of optics with the naked eye. Therefore, in most cases, the best option would be to seek help from the service center technicians.

If you decide to fix the cause of the problem yourself, it will be useful to use the following recommendations.

Do-it-yourself removal of headlight fogging

Before you start looking for the causes of fogging headlights, you need to thoroughly wash and dry the car's optics. After this, it is necessary to thoroughly clean the drainage and ventilation system of the headlights, if provided by the manufacturer.

In most models of modern headlights, access to the ventilation system channels is provided through the engine compartment or under the front bumper. If, after performing this procedure, fogging of the headlights is not eliminated, you should begin removing the optics from the car.

Since the headlights fog up from the inside, to eliminate this problem it is necessary to remove them from the car. First you need to disconnect the battery and then remove the optics. Having thoroughly cleaned the headlamp housing from dirt, check the structure for any violations of the tightness of the seams, the integrity of joints, connections and other damage. Colored gas can be used to identify microcracks.

The removed headlight must be dried thoroughly. To do this, take out the light bulbs and dry them with a hairdryer.

If minor damage to the seam or junction of the glazing with the body is detected, it is enough to restore it using a similar sealant.

If the sealing seam is significantly damaged, it is recommended to disassemble the headlight and completely remove the old sealant. After this, degrease and fasten the parts of the headlight unit using new sealant. The headlight housing should be carefully treated with sealant. Particular attention should be paid to the place where the wiring goes under the gasket and joints.

After completing all the measures, the headlights should be dried and, after the sealant has completely cured, installed on the car.

If cracks are found in the glazing or in the headlight housing of a large size, it is recommended to replace these elements with new ones. As a rule, do-it-yourself repair of significant damage does not provide an effective result. In most cases, the headlights will fog up again soon. Remember, the best option for eliminating headlight fogging is to replace the old optics with a new device.

Very often, the cause of fogging of the headlight may be a violation of the sealing of the docking chip connecting the turning light to the headlight. In this case, it is necessary to treat the connection with sealant.

In any case, after removing the headlight, it is necessary to thoroughly clean the drainage and ventilation system of the headlights. To do this, you can use thin wire.

Recommendations from experienced craftsmen

Vented plugs . If during the inspection of the optics no damage, cracks or blockages of the ventilation system were found, the experts recommend doing the following. Drill 4 holes with a diameter of 5.0-6.0 mm in the previously removed plastic plugs of the headlight units. Insert polyester fibers into the plug through these holes as ventilation tubes. Coat the edges of the fibers with sealant or “Moment” type glue. The edges of the substrate are sealed using waterproof silicone sealant.
Xenon headlights and silicone sealant. In xenon headlights, fogging may be caused by poor quality silicone sealant. If, when gluing a headlight unit, a large amount of silicone is poured, then during the curing process of the sealant, silicone oil and its vapors are released. As a rule, oil first settles on the inner surface of the housing. During operation, when heated, silicone oil evaporates and accumulates on the colder glazing. If the external temperature is low or it is raining, the headlight glass cools faster and silicone vapor deposits on it more actively. Unlike water vapor, which condenses into droplets, silicone vapor accumulates on the glazing in the form of a film. If the car is left in the sun and the optics warm up well, the reverse process occurs. Silicone oil evaporates from the glass and settles on the cooler parts of the headlight housing. Thus, the effect of “wandering” silicone fogging appears.

This problem can be resolved in this way. Remove the headlight unit and disassemble it, separating the glazing from the body. Carefully remove silicone stains, wipe all internal surfaces, with the exception of headlight reflectors and chrome. You should also remove old silicone sealant from the seams. Using a hairdryer, heat all parts of the headlight to completely remove any remaining silicone.

After this, it is recommended to connect the headlight unit using a more reliable high-quality sealant.