In autumn and winter, we can always see a lot of water droplets on the inside of the headlights of some cars on the street, blocking the light. For many drivers who encounter this situation for the first time, the first reaction may be that the headlight seal is aging, because this phenomenon rarely occurs in new cars.
So, what is the cause of foggy car lights? Is it a minor problem that can be left alone or a major problem that should be repaired immediately? Today, Diandian will talk about this topic.
1. Headlight structure
The lights commonly used on our cars are halogen lights, LED lights and xenon headlights. When the lighting is on for a long time, the xenon lamp has the highest calorific value, which can exceed 300 degrees, followed by the halogen lamp, and the LED lamp has the smallest value, about 70 degrees, and is a cold light source. Such high temperatures require timely air cooling to ensure the normal operation of the headlights. Usually, the structure of the car light is designed with an air outlet and a breathable film to dissipate heat. At the same time, in order to prevent water from entering, there will also be a sealing ring to seal the hole tightly, and a desiccant in the ventilation pipe (the main component of the desiccant is calcium chloride , replace according to local humidity conditions) to filter the air and take into account the effects of heat dissipation and waterproofing.
But there is no airtight wall in the world. If the sealing ring ages, or the desiccant fails over time, and the air humidity is high in autumn, winter, or rainy summers, then the moisture in the air will still have a chance to escape from the vents. Entering the lampshade, water vapor is formed under the action of the large temperature difference between the inside and outside, which results in the fogging phenomenon of car lights that we see every day.
2. Fog or water?
For car owners, they must first distinguish whether their car lights are fogged or flooded. The two approaches are completely different.
One way to judge is that the water droplets fogging up the car lights are small and stagnant, and generally only occupy half of the lampshade, and the remaining half is clean. This is related to the position of the air inlet, which may be left or right, or up and down. Another way to judge is to drive for 15 minutes and check to see if the fog has completely disappeared. If it has not, it is more certain that water has entered.
3. Dealing with headlight fogging
Occasionally fogging is normal, and the original lights will also do this. However, if it is a new car, you should apply for a quality claim under the warranty. Because fog generally occurs in old cars with many kilometers.
Usually in normal use, the fog will slowly disappear. If the fog is severe, or the headlights are slightly flooded, you can open the back cover of the headlights and put in desiccant, but it is not advisable to bake to avoid damaging the plastic parts of the headlights.
4. Treatment of water ingress into headlights
If there is serious water in the car lights, then you need to check the vents, sealing strips, and desiccant.
During the inspection, first check whether the desiccant is saturated or leaking, and ask the 4S store to replace it with a new one in time. Then remove the headlight assembly, check whether the lampshade is damaged, whether the sealant of the lampshade is in good condition, and re-seal it.
[Reminder]: Foggy headlights affect driving safety at night, and water intrusion may affect the wiring in the car. Therefore, in rainy and humid seasons, be sure to check your headlights regularly, especially after driving through water.
