Hello dear readers, motorists! Consider the problem the headlight sweats, what to do in such a case and why it happens.
Many of you have encountered the problem of fogging your car headlights. With this phenomenon, the brightness of the headlight deteriorates, and the appearance of the car takes on an untidy appearance. The reflective surfaces of the headlights deteriorate, and the conditions for safe driving deteriorate.
1. Depressurization:
- leaky fastening of the body and glass of the headlight unit;
- the headlight bulb holder is depressurized;
- rubber gaskets of anthers on the back cover of the headlight have lost their elasticity;
- cracks on the glass and in the headlight housing itself.
2. Moisture is sucked into the inside of the headlamp through the ventilation inside the headlamp space when the headlamp cools down sharply.
Headlight sweats what to do
In practice, those who are faced with this problem have to solve this issue radically, buy and install a new block-headlight, and this does not cost little money. Well headlight sweats what to do? Is it reasonable?
The point is not that you feel sorry for them, but that it is in vain to throw away money earned by back-breaking labor is at least unjustifiably wasteful.
And if you do not lose faith in yourself, then it is possible to correct this unpleasant factor yourself. Check all four points for possible depressurization. Find the place of moisture penetration, and if there are cracks, eliminate it. Only first you need to check the headlamp for leaks.
How to check? We lower the headlight into a container with water, glass down, without immersing the breathers, look where the leak occurs and take measures to eliminate it.
//www.youtube.com/watch?v=YW8iUr2lWUI
Headlights sweat after washing
Boyle-Mariotto's law says: If the temperature and mass of a gas are constant, then the product of the pressure of this gas by its volume is also constant.
In the case of a headlamp, at a constant temperature inside the headlamp, air does not escape from it and does not come in.
Experiment with this physical law on an empty plastic bottle. Close the lid while warm and place in the freezer. Take it out after a few minutes and see it will be compressed.
It is the same with the headlight, when the temperature changes, the air pressure constantly changes in it. It does not shrink like a plastic bottle, but the law works and the movement of air masses is intense.
The headlights are not hermetically sealed; their design includes ventilation valves (breathers) for air intake and bleeding.
When the light is turned on, air circulation begins inside the headlight, as in a normal room, the heated air rises up, the cooled down - down.
The heated and increased volume of air is vented into the upper breather, and when it cools and the pressure decreases, it is sucked in from the lower breather. Thus, blowing and ventilation of the inside of the headlight air is carried out. Air filters are installed in the breathers, slightly protecting against moisture.
Moisture that gets into the headlamp through the breather, with good ventilation, will always ventilate quickly and the headlamp will always be clean.
So, if you do not have cracks in the headlight housing and the breathers perform their function properly, slight fogging can still occur during washing. Especially if the temperature difference is large.
But this can be avoided by switching off the headlights and allowing them to cool to ambient temperature before washing.
Methods to eliminate fogging inside the headlight
Many car manufacturers place a bag of selikogel in the headspace. It actively absorbs moisture, protecting the glass from fogging.
Many, especially those specifically engaged in the preparation of jeeps for overcoming the ford, carefully seal the headlights, and the breathers are brought out above the level of the headlights by means of hoses.
It is also possible to remove the blowing of the headlights from the breathers into the intake manifold line.
Another method was invented by the Japanese company Nitto, they came up with filters for ventilation valves that allow air to pass through, but do not let water through.
And so, we figured out the reasons for fogging the headlights, possible methods for eliminating this phenomenon, now we will summarize and draw up a roadmap for troubleshooting:
- We remove the headlight;
- We check the tightness of the bulb holders;
- We carefully audit the ventilation valves (breathers);
- We check the tightness of the headlight in a water bath (do not drown the air vents!);
- If necessary, glue the cracks;
- Dry the headlight;
- We put in place.
First, let's figure out what the threat of chronic dampness inside the headlights of the car. Among the unpleasant consequences of this state of affairs, we will name the oxidation of contacts inside the device and, as a result, problems with electrical connections. In parallel, accelerated corrosion of the metal reflector can develop. Dampness can cause frequent lamp failure. However, the presence of a small one in the headlamp is, in principle, permissible. The fact is that any car light sources - whether halogen, xenon, or LED - get very hot during operation and, accordingly, do not heat the air inside the headlight. As befits a heated gas, it expands and its excess is released into the surrounding atmosphere through a special valve at the back of the lighting device.
If not for this mechanism, the headlight would have burst. When we turn off the head light, the headlight and the air inside it cool down. The cooling gas is compressed and air from the atmosphere is drawn into the headlamp through the same valve. Together with it, moisture vapor, which is ubiquitous around us, gets in. They can condense on the headlamp glass, fogging. This, we repeat, is normal, since the very next turning on of the dipped beam will again heat the headlight, the moisture will evaporate and go out through the valve. It is much worse if a puddle of water forms inside the headlight.
This means that the normal process of gas exchange was either disrupted for some reason, or the designers of the headlight did not think of something initially. There is little we can do about the water in the headlamp due to the fault of the latter. Is that trying to "skolkhozit" in it some kind of a drain valve, which will allow water and air to pass through, but prevent the penetration of dirt and dust from the road. But, as a rule, in such cases the car.
It happens that the headlight does not sweat and suddenly, at some point, moisture begins to condense. This means that either the valve is out of order, or extra holes have appeared in the headlight. In other words, a crack has formed in the case or the glass has come loose from the plastic "frame" in some place. The latter happens most often. If water appears in the headlamp after washing the car, then most likely this is the reason.
If it was a valve that stopped working or drain holes clogged with debris, then it is enough to clean them and turn on the dipped beam. The moisture will dry up and will no longer annoy with its presence. In the event of a crack or peeling glass, experts advise you to decide what is more acceptable for you in terms of financial and labor costs: change the headlight to a new one or try to seal the "holes" in the old one with a sealant.
- There were demons - we do not deny it. But they self-destructed.
Georges Miloslavsky "Ivan Vasilievich changes his profession"
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 headlight on in the summer, in the sun. In addition, the rear of the headlight is located in the engine compartment, where it is usually quite hot. At the same time, the air in the headlamp naturally expands, and therefore one cannot do without exchange with the external environment.
Where there is contact, there is always room for fogging. For example, if a cooling headlamp sucks in humid air - say, at a sink, 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 the chances of it fogging up are much higher. The once beloved Volga of one of the authors began to attract attention by the fact that the headlight glasses behaved differently - one is more transparent than the other. Soon everything became clear: during a visit to the service, one diffuser fell off by itself!
Is fogging dangerous? Undoubtedly. It distorts the light distribution, which interferes with both the driver (the road illumination falls) and other road users (blinding them).
At the same time, high humidity inside the headlamp housing destroys the coating of the reflectors. Well, there is nothing to say about an electrician: water and contacts will never reconcile.
If the headlight is working properly, then there is nothing to be afraid of. The fogging will disappear as quickly as it appeared. The headlight, as we have already noted, "breathes" - in cheap designs a tube directed downward is provided, and in more modern cars special breathers with small filters are used for ventilation.
But in any case, any lighting devices are protected from accidental ingress of moisture. If, of course, they are serviceable.
Fog lamp Kia cee "d. Two breathers are clearly visible. One for each section.
Fog lamp Kia cee "d. Two breathers are clearly visible. One for each section.
What faults can cause fogging? Everything is simple here: more often than not, the ventilation is simply clogged with dirt. Cracked headlights 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 headlamp until all joints are sealed, so that only the standard "breathers" remain. If this does not work, then the headlamp must be replaced. No desiccants in the form of silica gel or pieces of diaper will help a faulty headlamp.
And yet, how dangerous are drops of water in the headlight? We set up a simple experiment: using a syringe, we pumped 20 ml of water into the optics of the editorial Largus - that's quite a lot. They lit the headlights, waited, then turned them off - well, yes, the caps were dim. The light distribution has become ugly. However, after a couple of days, after a relatively short run, the effect disappeared: the water safely disappeared into the atmosphere. Which, in fact, was required to be proved.
Of the useful tips on 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 tinker with the headlamp or replace it altogether.
Tell us in the comments if you have encountered fogging of lighting devices and how you fought this phenomenon.
In the evening and at night, it is important for a motorist to have stable and high-quality light sources. In many cases, road safety depends on them. Indeed, in the dark, the car must be visible to other road users, and optical devices must illuminate the path at a maximum distance.
However, there are problems with the light elements of the vehicle, for example, the lamp dims and the headlight sweats, what to do in such a situation, we will analyze it step by step. Most of these problems can be fixed on their own in a garage.
Do not neglect the problem of fogged headlights, as this leads to serious consequences:
- the moisture that appears inside the closed cavity is capable of disabling this electrical appliance due to the oxidation of the contacts;
- an incorrect degree of illumination can significantly increase the accident rate on the road;
- the accumulated liquid, due to its high electrical conductivity, can cause a short circuit in the wiring, and then the main electrical appliances and components will be damaged.
A common reason car headlights fog up is when condensation forms on the inside of the headlight.
Particles of water vapor in the air, when they come into contact with warm currents, combine into drops, settling on transparent plastic. Thus, a liquid is formed from the gas, which negatively affects the performance of the automotive unit.
Paths of water ingress into the lighting fixture
In some cases, the ingress of liquid occurs in other ways, for example, due to a violation of the tightness of the structure. During the operation of any type of lamp, heat is necessarily generated, to a greater extent for incandescent lamps, to a lesser extent from halogen or xenon elements.
When the air is heated in an enclosed space, the gas expands; for this, a check valve is provided in the cavity of a modern headlight. It allows you to remove excess volume to the outside. For drivers who do not know what to do if the headlights fog up from the inside, we recommend carefully checking the valve on the headlight.
Another reason for fogged optics is the depressurization of the seams along which the ceiling lamp is attached to the car body. This is due to the fact that it is technologically impossible to achieve perfect fixation of the block to the case. Automobile companies use special substances - sealants to ensure this parameter.
During the period of operation, these plastic materials lose their properties and are destroyed in some areas. Due to cracks and chips that have appeared, water penetrates into the lighting cavity. Unfortunately, the domestic and inexpensive Chinese auto industry is susceptible to such "diseases".
To quickly get rid of depressurization of optics on cars of the Volzhsky Automobile Plant, a can of sealant is suitable. It must contain silicone in its composition. Having processed the problem area, the driver needs to wait a while for the substance to solidify. After that, you can enjoy good light.
The most unpleasant situations, when the headlight sweats in the car, occur when the plastic cover is damaged. In many cases, the slits have microscopic parameters that cannot be detected with the naked eye. However, they are quite enough for moisture from outside.
The trouble is eliminated in two ways:
- surface restoration with special sealants and polishing;
- complete replacement of the light block.
In both cases, the work can be done independently, and you will have to spend a lot on materials.
When fogging of the headlights occurs during the operation of a vehicle under warranty service, the car owner is entitled to free compensation for the defect. To restore functionality, you need to contact authorized dealers.
It should be noted that the problem is more common in budget car models, even among world famous auto brands.
Lack of tightness occurs after accidents. Even minor damage to the geometry of the body can lead to these consequences. It is necessary to check the fit of the plafond to the body after collisions.
Elimination of causes by warming up
Dry heat is a popular solution. The motorist manages to get rid of the vapor film on the inner surface of the headlight. However, the method turns out to be effective in case of one-time occurrence of condensation.
Heating the headlight with a hair dryer
In this case, we perform the following algorithm:
- dismantle the optical device;
- slightly weaken the fixation of the lamps and partially remove them from the socket;
- turn on the dipped beam for such a period that the cavity warms up, drying out the remaining moisture;
- turn off the light and return the cap to its place.
Drying usually takes several hours. Some drivers start the engine several times during the operation in order not to completely discharge the battery.
Use of sealants and polishes
The driver should inspect the problem area to identify damaged areas behind the headlamp. Sufficient quality after restoration is formed by sealants with silicone. They must be moisture and heat resistant.
Headlight sealant application
For example, a colorless drug Runway performs its functions in the temperature range from -60 to +204 C. The cost of the product for 85 g is a little more than 100 rubles. The drug is grabbed in an hour, and the complete solidification of the substance is carried out in a day. Excess is easily removed with a sharp knife.
To detect microcracks in the sealing zones, special equipment is used, based on an optical, electronic or laser working element. Such devices are quite expensive and can only be found at service stations. As a preventive measure, you can use a sealant over the entire visible joint surface.
The outer surface of the headlamp is capable of deterioration under the influence of external factors. In this case, invisible or visible cracks appear on the plafond. In some cases, they can only be detected with special equipment.
To reanimate an expensive electrical appliance, it is not always used to replace it with a new one. In some non-critical situations, the headlight can be restored with your own hands. The most popular are two ways:
- Application of polishing. A soft nozzle is installed on the grinder. During processing, the settings should be set to maximum speed. It is believed that the edges lightly engage with each other, restoring the tightness for a short time. However, when driving on bumpy roads, this method loses its effectiveness due to shaking.
- Use of transparent sealants. There is a wide selection of materials on the market that are both waterproof and high optical properties. Such a substance is applied to the problem area and allowed to dry. The disadvantage of this method is the adhesion of dust and dirt to the material. This reduces the efficiency of the headlights. Also, the effective period of use of such substances is rather short.
A more effective method is to seal the cavity from the inside. You will need to dismantle the optical unit from the seat. It is also disconnected from the electrical network and all technological fixtures.
It is advisable to entrust such a restoration to experienced specialists who have dealt with more than one car model. Indeed, in addition to electrical components, there are design features associated with different manufacturers.
You can meet the recommendation to add a small amount of brake fluid to the cavity. This method is based on the fact that it has a high degree of hygroscopicity, moisture absorption. The negative side of the method is that dust and dirt are attracted along with moisture. Such consequences have a negative effect on the transparency of the device. The film formed inside the headlamp will interfere with high-quality outdoor lighting in the future.
Another way out of the situation is to apply a tint film. To ensure a seal, a material with maximum transparency is suitable. This method will not only prevent the current problem, but also prevent the propagation of possible future cracks and microcracks. We recommend using headlamp chip protection on both optical devices. This will give them the same look and feel less noticeable.
If none of the proposed restoration options is suitable, then a cheaper way is to search for the necessary spare part at car dismantling. In many cases, optics last a long time, so there is a high probability that you can buy a quality part inexpensively.
Many motorists are aware of such a popular problem as fogging headlights. Despite its seeming insignificance, this is a really dangerous phenomenon that needs to be eliminated as quickly as possible.
When a person does not know why the headlights sweat, this reduces the safety level of the driver and passengers many times over. Of course, for daytime, this problem may not be relevant. But, with the onset of dusk, the illumination of the road with headlights is a direct necessity in order to indicate the direction of movement.
When the headlights fog up, the light does not pass through the glass, but is refracted by condensation.
Most of it settles inside the headlamp in the form of thermal energy, and the remaining particle passes through the headlamp with an irregular refraction, illuminating only a small part of the road ahead.
An even bigger problem can appear if dust additionally settles on the headlights. Then movement becomes completely impossible. As a result, you have to stop every few kilometers to clear the headlights. It should be said right away that it is impossible to dry the headlights under the influence of heat from the lamp until the headlight is open. Otherwise, moisture will constantly be inside, which will lead to oxidation of the metal, and the rapid failure of their lamps and their mountings.
Causes of fogging headlights
So, let's figure out why the headlight sweats from the inside. The fact is that no liquids should be present inside the headlamp unit, even in minimal quantities. But, as you might guess, the presence of condensation there indicates the ingress of water inside. There may be several reasons for this.
Incorrect headlamp geometry
Incorrect body geometry is becoming the most popular problem. The point is that the car was initially incorrectly assembled on the conveyor, as a result of which the manufacturer left a small gap between the individual elements of the headlight, through which moisture gets inside. However, it should be noted that at the moment new cars no longer suffer from such disadvantages.
In particular, most of the Chinese cars, which their owners could complain about before, have reached a level of quality where there can be no talk of any manufacturing defects. A prime example of this can be any of the Lifan brand cars, such as the X60 or Breez.
Depressurization after an accident
However, depressurization can occur in another case, namely, when the car has been in an accident. Even minor damage to the front end, in most cases, adversely affects the condition of the headlights. Even if they have not been broken, the chance that there has not been a violation of their design will be minimal.
In addition, if glass or another element of the headlight is broken, service centers can repair them, instead of completely replacing them. And repairing glass or plastic materials involves using a simple sealant. For the first time, its properties will be sufficient, but after a few years it completely loses its original characteristics, as a result of which the tightness of the headlight disappears.
Loose connection
Also, the problem may lie in the loose connection of parts on the back of the headlamp, where there are technological holes for the possibility of replacing the lamp. In the case when you are wondering why the fog lights sweat, the answer will be exactly the same - they have depressurized.
From the point of view of physics, the following process takes place inside the headlight. We are talking about the transition of a liquid from one state to another when certain conditions occur. In a specific case, this will be a decrease in the ambient temperature. At the moment, the moisture in the air inside the headlight begins to look for the coldest place, which turns out to be the glass. It is there that small droplets form.
The headlight must be removed before starting to work with it.
Eliminating the problem
So, we are pretty sure that the headlight is sweating from the inside. What to do in such a situation? Everything is simple here. There is a certain algorithm of actions.
Algorithm of actions
- It is necessary to open the lamp covers, then pull them out partially.
- The dipped beam turns on.
- The headlights warm up a little, after which the lamps turn off again.
- They will stay in this position until morning.
There should be no fogging in the morning. If condensation still appears, then it will be possible to warm up the headlight through additional methods, such as using a hair dryer, and so on. Once we have achieved a positive result, we can proceed to the next step.
We carefully inspect all connecting seams. If problem areas are visible on them, then they are cleaned and coated with a special sealant. Also, the headlamp needs to be checked for cracks or other loose joints. Defects must be sealed with a sealant, while cracks will be much more difficult to repair. It can be problematic to cope here on your own, since you have to limit the growth of the crack, and only then isolate it with special glue.
Get rid of cracks with headlight tinting
Crack marks can be aesthetically unappealing. It is impossible to get rid of them, but they can be hidden by means of tinted headlights. This is not a very difficult activity, which will allow you to restore the former look of your car.
Sometimes you need to seal the rear connections
It is worth noting that the reason may be, as we have already said, a problem in the connection on the back of the headlight. As a rule, it will be sufficient to replace the gasket, if provided by the design. If the connection must be insulated due to the elastic properties of the plastic, then the problem will be more significant. The fact is that plastic loses its properties over time, turning from a flexible material into a solid that easily crumbles.
There are two options here. It will be optimal to replace a part that no longer has elastic characteristics. However, it can be problematic to do so, so you will need to choose or make a gasket yourself, which will be installed on the site near the threads.
After this fogging, it should pass, and you will no longer wonder why the headlights of the car sweat.
In the process of work, the main thing is not to overdo it.
Among other things, it should be noted that the old "Soviet" method of fixing this problem will be unacceptable. We are talking about a situation when, to "treat" fogging, the headlight was filled with brake fluid. This, to some extent, can seal cracks, but another, more significant, problem appears - a violation of the transparency of the glass. And it can only be dealt with by polishing, which will lead to the elimination of the positive effect of using brake fluid. By doing this, we go in cycles in the same actions.
