What to do if your car headlight is sweating

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.

Eliminate fogging of headlights

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Fogging of headlights from the inside is not as harmless a phenomenon as it seems at first glance, when steam and moisture accumulate on the glass of the optics, the illumination of the road at night becomes worse, and accordingly, the level of safety of the driver and passengers in the car decreases.

1 Why do car headlights sweat from the inside?
2 Ways to remove headlight fogging
3 Fogging headlights on Priora
4 Elimination of defects in Lada Granta taillights
5 Fogging headlights on Hyundai Solaris
6 Eliminate fogging of the front optics on a Ford Focus 3 car
7 Clogged vents
8 Cloudy headlight glasses

Car owners often ask the question: if the headlight sweats, what should you do in this case? In this article we will look at the reasons for fogging of car optics and possible methods for eliminating this problem.

Why do car headlights sweat from the inside?

The headlight often fogs up in humid weather or after a car wash. Moreover, this phenomenon does not depend on the mileage of the car; the headlights inside can be damp even on a practically new car. A car headlight (tail light) is a closed space in which, as the temperature from the incandescent lamp increases, the internal pressure also increases. To prevent excess pressure from being created, all automotive optics have special valves.

The purpose of the valves is to let air in and out of the optics, but dust, dirt and water should not fly into it. In the evening after a trip in the off-season, the headlight cools down, the pressure in it decreases, and moist air enters through the valve. Moisture condenses on the glass, causing the optics to fog up. There is nothing wrong with this if the moisture quickly evaporates after the car warms up and starts moving. But condensation does not always go away, and then it already causes a lot of problems for the car owner. The most common cause of the defect is caps falling off the ventilation valves; in this case, the optics require repair. Also, moisture can penetrate into the headlight through a barely noticeable crack in the glass or in the housing - if condensation lingers in the optics for a long time, it must be repaired.

Ways to eliminate fogging of headlights

There are several ways to eliminate fogging of headlights in a car, it all depends on what defect is detected in the optics. If a crack is found on the case, it must be soldered using a soldering iron or hair dryer; you should be aware that in this case it will not work:

seal the crack with glue;
seal the defect with tape or adhesive tape.

The headlight is made from special ABS plastic, which cannot be glued together.

Glass is often glued to the headlight with silicone sealant; over time, the sealed layer sags, and moisture gets into the optics through small gaps. To eliminate the defect, in this case, you should remove the glass and lay a new layer of sealant.

If the cause of fogging of the flashlight is the ventilation valve, it is necessary to eliminate the defect - clean the valves from water and dirt, provide air ventilation. Unfortunately, valves for headlights are not sold separately, so you have to rebuild them.

There are several popular ways to combat fogging of car optics; car owners fix the problem like this:

place a bag of silica gel in the headlight housing (the substance absorbs moisture well);
pour some brake fluid into the optics.

Each of the methods has its own side effects: the brake fluid causes the glass to become cloudy, and the silica gel itself swells with water over time and can damage one of the elements inside the structure.

In some cases, foggy headlights are a design flaw, but car manufacturers are aware of this and are taking all measures to combat the unpleasant phenomenon. For example, the Kia company standardly installs containers with silica gel on some models; a similar Kia Sorento headlight can be seen in the photo below.

Fogging headlights on Priora

On Lada Priora cars, the optics sweat very often; the problem occurs on almost every second car. The reason for the defect is that the back cover does not fit too tightly to the body, because of this moisture penetrates into the optics. To fix the problem, you can try replacing the rubber seal. But still, the main cause of the defect is poor ventilation; you must first of all pay attention to the ventilation valves.

Here is one way to deal with headlight fogging on a Priora; it is better to do this in warm (hot) sunny weather:

We install the car with optics on the sunny side;
remove the rear covers from the headlights;
warm up the insides of the optics with an ordinary hairdryer;
We heat the silica gel in a frying pan, pack it in cloth, and place it in the case so that it can then be easily taken out.

You need to keep an eye on the silica gel and change the bag when it swells.

Elimination of defects in Lada Granta taillights

On the Lada Granta, as well as on the Kalina, the taillights often sweat in the winter, and in the summer they get clogged with insects and dust. How can you deal with such an unpleasant phenomenon?

Let's consider eliminating a defect on Grant's car:

disconnect the protective cover in the trunk, turn off the power from the optics, remove the rear light (it is secured with three 8-mm nuts);

thoroughly rinse the glass, place the lantern in a bath of water, add two or three drops of Fairy to wash dishes;
after washing, let the plastic dry thoroughly;

install the flashlight in place, take a bag of silica gel, attach it to the back of the optics, for example, between the wires;

seal the lantern - seal it with tape at the back;

We put the plastic in place and close the lantern with a plastic plug. After the work has been done, the lights should not fog up for a long time.

Fogging headlights on Hyundai Solaris

Headlight fogging can occur on any car model, and the Hyundai Solaris is no exception. There is nothing wrong if the optics sweat in damp weather, and 5-10 minutes after turning on the light, the condensation from the glass disappears. If the Hyundai Solaris is under warranty, if the defect is severe, in many cases official dealers change the optics under warranty, but often car owners have to solve this problem themselves.

As mechanics explain, the headlight sweats because the headlight glass shifts on its plane due to vibrations of the car, and air and moisture enter the optics housing through the joints and irregularities of the sealant. To eliminate the defect, it is necessary to remove the headlight, dismantle the glass, and re-glue it with silicone sealant.

If the headlight is foggy and you need to drive urgently, we use the following method:

open the rear housing cover on the headlight;
turn on the high beam;
wait until the condensation from the glass disappears.

In many cases, this method helps, and the owner of the car can hit the road in the dark. If this method does not work, you can try warming the insides of the headlight with a regular hairdryer with the rear covers removed.

Eliminating fogging of the front optics on a Ford Focus 3 car

It is worth noting that headlights usually do not fog up opposite the lamps; most often, condensation appears on the glass below. On a Ford Focus 3, moisture accumulates most in the area of the turn signal; let’s look at how to eliminate the defect here.

We purchase corrugated door wiring and a standard nylon tie. We carefully make a hole in the lower ebb of the turn signal, use a soldering iron, since when drilling, the chips will get inside the body.

We fake holes on the sides of the ebb and install a screed in them.

We put the corrugation on top and fill it with padding polyester inside.

To ensure that the corrugation does not dangle, we tighten it with another tie to the body.

We got a new ventilation hole next to the turn signal, and now the glass on the headlight will not fog up.

Clogged vents

Each headlight is necessarily equipped with a ventilation hole, which plays the same role as a breather in an engine or gearbox to relieve excess crankcase gas pressure. If the valve becomes clogged, the resulting condensation cannot escape from the enclosed space and is deposited as fog on the headlight glass. To prevent the optics from sweating, these valves must be cleaned periodically.

On modern cars, there are usually two or three valves in each headlight; the location of the ventilation ducts depends on the car model.

On the outside, the plastic rounds look like plugs, but in fact there are channels located here.

Most often, dirt clogs the ventilation ducts and gets into the headlight at the bottom, which is why the optics become dirty and the glass fogs up.

To protect the optics from dirt from the road, it is necessary to install protection for the front fenders. If the headlights sweat, you should drill additional ventilation ducts, but it is better not to do them at the bottom. It is convenient to install the valves in the rear covers; in this case, you do not have to drill the headlight itself.

Cloudy headlight glasses

During operation, car headlight windows can not only fog up, but also become cloudy; because of this, the optics do not shine so brightly, which also affects traffic safety. Plastic glasses can lose their appearance for various reasons:

the outer surface of the headlight is wiped with a dry cloth (this cannot be done);
Dust and sand flies onto the glass from the road, as a result, small scratches form on the glass surface and yellowness appears;
The glass becomes dull over time, natural aging occurs, and the glass also burns out under the sun's rays.

To return the glass to its normal appearance, they are polished. After polishing, the headlight will not look like new, but its light transmittance will increase. If the glass is inexpensive and sold separately, it is easier to replace it than to polish it. The optics are polished using special polishing pastes, first processed with a coarse-grained compound, then with a fine-grained paste.

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.

Why do car headlights fog up and what to do?

The car is an important part of the daily lives of millions of people. But the machine requires proper care, since sometimes breakdowns and malfunctions occur. All of them are to a certain extent related to the characteristics of operation, or to the not very high quality of the spare parts used. If we talk about headlights, they are designed to ensure safe movement by car in the dark and in bad weather conditions. That's why they need special care. It consists of timely replacement of lamps, repair of faults and maintaining the required level of transparency of the glass or plastic case.

How to deal with fogging car headlights.

The driver does not always pay attention to a problem such as fogging in time. But ignoring this situation can lead to serious consequences. The resulting condensation turns into water droplets. Moisture contributes to the development of dangerous situations, which can result in extremely expensive repairs. Therefore, you should figure out what to do if the headlight sweats. The sooner you take on the problem, the better.

Causes of fogging

Before you begin repair or maintenance work, you need to understand why the car headlight sweats from the inside. There are several main reasons, each of which has its own characteristics. If moisture has formed on the outside of the case, there is nothing to worry about, since to eliminate it, just walk with a cloth over the body of the optical device of the machine. The question of what to do when the headlights sweat from the inside looks much more serious. This clearly indicates the appearance of a hole or a certain gap in an initially sealed device.

In some cases, the reason why car headlights sweat from the inside should be sought in the manufacturer itself. On cheap budget vehicles, there may be a manufacturing defect due to which the vehicle's optics housing was assembled incorrectly. The resulting gaps became a passage for moisture from the environment. But it also happens that the car encounters a similar problem due to the fault of the car owner himself, incorrect repairs, due to the use of low-quality sealant, etc.

In total, there are several reasons why car headlights may fog up on the inside of the housing:

Cracks. Sealing failure often occurs due to mechanical damage to the housing. It is made of plastic and glass, so the likelihood of cracking is quite high. Accidental impact, consequences of an accident, intentional damage. There are many reasons for a crack to appear. But the problem is that it cannot be eliminated. All that remains is to buy a new housing, or change the entire headlight.
Back cover. Also, from time to time, depressurization of the rear covers of car headlights occurs on different cars. The plastic used for these elements cannot be glued. But you can use the soldering method by picking up a soldering iron or a hair dryer.
Ventilation hole. Manufacturers of headlights must provide a special hole that serves for ventilation. It allows the headlamp not to overheat and fog up, no matter how paradoxical this may sound. If this hole becomes clogged with debris, or sealant is accidentally poured there, the process of condensation will begin. It is not difficult to solve the problem here, since you only need to clean the ventilation duct.
Sealant. Good expensive cars use high quality optics. It is installed using sealants that can last the entire life of the machine itself. Much lower quality sealant is used on budget cars. But sometimes even expensive mastic begins to deteriorate due to high or low temperatures, as well as other external and internal factors. The sealant does not perform its functions, and therefore needs to be replaced.
Valve. The design of automotive optics provides for the use of a special valve necessary for pressure compensation. When the headlight is active, the temperature inside the housing increases, which entails an increase in pressure. To prevent this pressure from leading to destruction of the housing, it must be removed from the headlight. A valve is used for this. When pressure is released, moisture can enter. If the valve is not operating properly, fogging may occur. Under normal conditions, moisture is dried through the previously described ventilation hole.
Fastenings. If, during repairs or even at the stage of assembling the car, the fastening nuts holding the headlights to the car body were not screwed tightly, moisture may penetrate through the resulting gaps. And gradually its quantity only increases.

You can clearly see that there are many reasons why the headlights of a car sweat from the inside. Some of them are not particularly serious, and therefore the problem can be eliminated with minor intervention. Other problems require drastic action in the form of a complete replacement of the optics. Much depends on at what stage of the problem the driver noticed the fogging. If moisture has already caused internal damage, repairs will be expensive because you will need to buy a new set of headlights.

Possible consequences

A car owner should know what to do if a headlight fogs up. This is not as minor a problem as some may think. The formation of condensation and subsequent release of water inside the optics can potentially cause serious problems. Let us highlight the main ones:

Decrease in glow quality. Fogging causes a layer of water to form on the lenses. Water already has the ability to refract light, causing it to become diffuse. And in combination with the design of the optics, what is formed on the road is not a clear spot of the correct shape, but some kind of shapeless blurry blot.
Oxidation. Everyone knows that water and wires are not good friends with each other. Moisture promotes the development of corrosion and oxidation processes on metal surfaces. Moreover, it’s mostly the wiring that suffers first. The contacts oxidize, causing electric current to stop flowing normally through the wires. The result is a complete system failure. The electrical system of the entire vehicle may be damaged.
Deflector. It’s not just metal that should be wary of contact with water. Reflectors can also be damaged. When the deflector heats up and there is moisture inside, a steam cloud will be created. If the deflector frequently comes into contact with steam, the reflector will eventually become dim, which will negatively affect the quality of the glow.
Destruction. Let's say right away that this happens rarely. But the lamp can be destroyed if water comes into direct contact with a hot bulb. This is realistic if the housing or diffuser is damaged.
Light bulbs. Some solve the problem by simply replacing the burnt out light bulb. But if you do not eliminate the cause of fogging, you will have to buy new lamps very often. This will gradually lead to the development of more serious faults affecting reflectors, lenses, wiring and metal corrosion.

The car owner’s first priority is to find out exactly why the car’s headlight fogs up on the inside. Without knowing the cause, it will not be possible to eliminate the possible consequences. You should not ignore the fact that there is a layer of water under the glass or plastic of the case. You already know the consequences. And hardly anyone wants to risk the integrity of the car and large financial costs.

Troubleshooting

Now we will talk directly about what to do if the headlight of the car is sweating. There are several ways to fix this problem. A lot depends on why the headlights sweat from the inside. Based on the cause, you can choose the best way to fix the problem. It is important to understand that it is not always possible to do without financial costs. In certain cases, you will have to buy new optics, since repairing a car headlight that fogs up from the inside is impossible. Eliminating the cause of this condition requires drastic measures. Having finally figured out why the headlights sweat from the inside, you will understand which method is more relevant in your specific situation. Let's start with the simplest method of how to fix the problem. Relevant for those who cannot now spend time on repairs due to lack of time. But the moisture must be removed in order to safely reach the destination, where it will be possible to carry out full-fledged restoration measures. This method is called dry. It consists of performing the following sequential actions:

First, the lampshade is removed from the machine's optics;
using a screwdriver of a suitable size, slightly loosen the fasteners on which the lamp is held;
Now the lamp itself rotates a little from the socket, but so that it remains in working condition;
The low beam in the car turns on;
in this condition the car should stand for about 1 - 2 hours;
during this time the lamp has time to warm up, thereby drying out;
When the drying is finished, everything is assembled in the reverse order.

This dry heating method will work if the headlights only sweat periodically and are not constantly in a layer of water on the internal surfaces.

The repair method is temporary, since it does not eliminate the cause. Therefore, whenever possible, take repairs seriously. The body, seams and all surfaces should be inspected in detail. If you manage to find gaps or minor cracks, you are partially lucky. This is good because you have found the reason why the headlights are sweating from the inside.

Armed with a can of silicone sealant, available at almost any automotive store, treat all seams and gaps through which moisture from the environment can potentially penetrate into the car optics. It is extremely easy to work with this sealant, plus it has impressive durability. If the gaps or seams that are causing the problem cannot be detected without special equipment, you should contact a good car service center.

Using optical or laser tools, they will quickly find the source of the problem and help eliminate it. Seams and gaps do not pose a particular threat, since they can be easily eliminated using sealants and replacing fasteners that may have worn out. If moisture has not caused serious damage to the optics, simply get rid of the gaps.

Things are much more complicated with cracks. It is almost impossible to get rid of them through repairs. Experienced specialists advise in such cases to immediately buy a new set of optics for the car. But there are craftsmen who at least temporarily restore the integrity of the body. Whether to use such methods or not, each car owner decides independently. If you don’t have the money to buy new headlights right now, you can use two methods as a temporary solution:

Polishing. To restore the tightness of your headlights, try gently polishing the surface where the crack has formed. To do this, take a grinder and the softest possible nozzle. This treatment will allow the edges to adhere. This will give a temporary effect, which will allow you to raise money and still buy new optics.
Synthetic compounds. There are special liquids based on synthetic materials that have a transparent structure. You can find them in the same automotive stores that sell sealant and silicone. This is also a kind of sealant that is applied in a thin layer and hardens on the surface. As a result, a coating is formed that closes the crack, but does not prevent light from fully passing through the material. The compositions are easy to apply and dry quickly. Under the influence of moisture, high and low temperatures, high-quality liquids should not quickly deteriorate. But it is important to perform the processing correctly, otherwise the desired effect will not be achieved.

Do not forget that the source of moisture may be the inside of the car. If everything is fine with the case, and water does not penetrate inside through the plastic or glass due to reliable sealing, you will have to dismantle the device and look for the reason on the back side.

Headlights are a rather complex mechanism, connected directly to the vehicle's electrical system. Therefore, without proper experience, it is strongly not recommended to take on such work with your own hands. In certain situations, you cannot do without professional equipment. Therefore, drivers should always have contacts of an experienced electrician and a mechanic from a proven, well-established service station.

And one more important point. If the car is new and still under warranty, the cause of fogging can be eliminated free of charge. But this is realistic provided that you did not hit the optics and did not get into its structure with your hands.

Statistics clearly show that on budget and middle-class cars, where manufacturers use far from the highest quality spare parts and sealants, such problems arise precisely because of manufacturing defects. The manufacturer does not comply with production standards, which is why car owners then suffer. If you have nothing to do with this situation, that is, you did not touch the headlight or touch it, but it still began to fog up, contact an official service center. If this is not the case, then go to the car dealership where you bought the vehicle. They are obliged to fix the problem completely free of charge.

Foggy headlight: treat or replace?

“There were demons—we don’t deny that.” But they self-destructed.

Georges Miloslavsky “Ivan Vasilyevich is changing his profession”

Foggy headlight

Generally speaking, absolutely all headlights and other car lights are a priori leaky. It cannot be otherwise: when heated, the temperature inside any headlight can easily change by 100 degrees! From minus 35, achievable in winter even in central Russia, to 60-70 degrees with the headlights on in the summer, in the sun. In addition, the rear part of the headlight is located in the engine compartment, where, as a rule, it is quite hot. At the same time, the air in the headlight naturally expands, and therefore cannot be avoided without exchange with the external environment.

Where there is contact, there is always the possibility of fogging. For example, if a cooling headlight sucks in moist air - say, at a car wash, then the transparent cap (previously it was a diffuser) according to the laws of physics has the right to become somewhat cloudy. Well, if the headlight has defects, then it has a much higher chance of fogging up. The once beloved Volga of one of the authors began to attract attention because the headlight glasses behaved differently - one was more transparent than the other. Soon everything became clear: during a visit to the service, one diffuser fell off by itself!

Is fogging dangerous? Without a doubt. It distorts the light distribution, which disturbs both the driver (the illumination of the road decreases) and other road users (it blinds them).

Cloudy headlight

At the same time, increased humidity inside the headlight housing destroys the coating of the reflectors. Well, there’s nothing to say about electrics: water and contacts will never make peace.

If the headlight is working properly, then, in general, there is nothing to be afraid of. The fogging will disappear as quickly as it appeared. The headlight, as we have already noted, “breathes” - cheap designs have a downward-pointing tube, while more modern cars use special breathers with small filters for ventilation.

But in any case, any lighting devices are protected from accidental moisture. If, of course, they are working properly.

What faults can cause fogging? Everything is simple here: most often the ventilation is simply clogged with dirt. Headlights with cracks also “walk on their own.” Some cases of fogging are associated with unprofessional disassembly/assembly of the headlight.

In such cases, there is only one piece of advice. Repair the headlight until all joints are sealed, so that only the standard “breathers” remain. If this does not work, the headlight must be replaced. No desiccant in the form of silica gel or pieces of diaper will help a faulty headlight.

And yet, how dangerous are drops of water caught in a headlight? We carried out a simple experiment: using a syringe we pumped 20 ml of water into the optics of the editorial Largus - this is quite a lot. We turned on the headlights, waited, then turned them off - well, yes, the hubcaps became cloudy. The light distribution became ugly. However, after a couple of days, after a relatively short run, the effect disappeared: the water safely evaporated into the atmosphere. Which, in fact, was what needed to be proven.

Of the useful tips regarding anti-fogging, we will mention, perhaps, only one: be careful when washing the engine compartment under pressure. A strong jet can rip off the “breathing caps” and cause trouble, after which you will have to seriously tinker with the headlight or replace it altogether.