As one of the most important lighting fixtures on a car, headlights can not only illuminate the road ahead at night, but also play an important role during the day when the light is poor, such as rain and fog. With the advancement of car light manufacturing technology, headlights are not only becoming more and more beautiful, but also have a longer service life.
But there is still one situation that makes people feel imperfect, that is, in the winter, there are some fog and water droplets in the car lights adhering to the lampshades from time to time. This situation is a bit like when a person wearing glasses walks into the house from a cold outside, a layer of water mist appears on the spectacle lenses, which affects the vision.
What's wrong with the foggy car headlights? Is the car light broken? Is there any way to prevent the headlights from fogging up? These issues need to start from the structure and use environment of the headlights.
Two reasons why car headlights "fog"
First of all, car headlights have a semi-sealed structural design. The headlight housing is sealed, but there is a ventilation hole on the headlight assembly to prevent dust. When the headlights are turned on, they will generate a lot of heat. The air inside will heat up. At this time, the air pressure inside the lampshade is higher than the air pressure outside, so it will escape through the vents.
When the headlights are turned off, the temperature inside the lampshade drops and the air pressure is lower than the outside air pressure. At this time, outside air will be absorbed through the vents. If it encounters rain or snow, water vapor will enter the headlights. When the car is started, the headlights will It will fog up. The fogging of the headlights caused by this reason is within the designer's consideration, so it will not affect the normal function of the car lights.
Another reason is: the headlight is flooded. This is a situation where the amount of water ingress is relatively large. Some car lights have poor sealing effect and are not completely sealed. The car lights will generate a lot of heat when they are working. Therefore, the increase in the internal temperature of the car lights will lead to an increase in the air pressure inside the lamp cover, which will cause the lamp cover to rise. The gaps that were not tightly sealed opened, and rainwater flowed into the lampshade along these gaps. Also, when washing the car, some water may enter the interior of the car lights through the cracks, and the water will be heated and atomized.
The exhaust holes of the headlights are usually inside. It is difficult for car wash water and rainwater to enter the headlights through the exhaust holes. Therefore, if the headlights often fog up after raining or washing the car, it is very likely that there is a problem with the headlight seal. .
After understanding the reasons why car headlights are foggy, we can make corresponding treatment methods.
If the fog is caused by normal physical phenomena, as long as you turn on the headlights every day, the fog will dissipate in about a week.
If fogging is caused by water ingress, we should first open the car lamp cover to dry it. After the fog is removed, we should find the air leakage, that is, the place where the sealing is not tight, and then re-seal it. If it is not sealed properly, water will still enter the car headlights next time, and it will fog up when driving.
The aging and elasticity of the sealing rubber strip on the back cover of the lampshade decreases, resulting in loose sealing and cracking and damage at the lampshade or the joints of the lampshade. For this kind of hardware damage, the headlight needs to be repaired. During the warranty period, it only needs to be opened. Just go to the 4S shop and ask them to repair it for you.
After the warranty period, it is just a simple lampshade seam cracking. Generally, car lamp modification shops will provide such repair services. If the damage is serious and cannot be repaired, then the only option is to replace it with a new one.
