As far as the overall structure of the headlight is concerned, whether it is an ordinary halogen headlight, a xenon headlight, or a headlight with an LED light set, there is a ventilation rubber tube on the back cover. When the headlight is turned on, Even the headlights will generate a lot of heat when in use. The function of the breather pipe is to discharge this heat out of the headlights as much as possible to maintain the normal operating temperature of the headlights and ensure the stable use of the headlights.
Reasons for headlight fogging
Moisture in the air will enter the headlight through the breather tube and adhere to the lampshade. As the water vapor accumulates, the water droplets will flow down the lampshade. This situation is mostly caused by large temperature differences, and is most likely to occur in winter and rainy seasons. After the car lights are turned on for a period of time, the mist will be discharged out of the lights through the vent pipe along with the hot air, which will basically not damage the headlights and electrical circuits.
In this situation, drivers should not act rashly. For example, they must not bake the headlights. Doing so can easily damage the headlights. Because the exterior of the headlights are made of plastic, extra heat can easily bake the lampshades, and most of this damage is irreparable.
In addition to weather changes, human factors can also cause car lights to turn into "tear eyes", such as vehicles wading in water, car washes, etc. When a vehicle is wading through water, since the engine and exhaust system themselves are relatively large heat sources, rainwater will form a large amount of water vapor on them. Some of the water vapor will enter the headlights along the breather pipe.
Car washing is more straightforward. Some car owners like to use high-pressure water guns to wash the engine compartment. After flushing, the water vapor in the engine compartment is not dealt with in time. After closing the engine compartment cover, the water vapor cannot be quickly dispersed to the outside of the car. The water vapor trapped in the engine compartment may enter the headlights.
How to distinguish between water intrusion and fogging?
Under normal circumstances, many people don't know how to distinguish whether the headlights are filled with water or fogging. They often think that there is water in the headlights as soon as they see water droplets. In fact, there is a way to initially judge whether the headlights are filled with water or fogging, which is to check for traces of water flow.
We know that when water enters the headlight, it usually enters from the top of the headlight and then flows under the headlight. This will form obvious traces of water flow, similar to a waterfall. Even if the water is dry, there will still be some traces. Just like there are traces on the path of a snail, an experienced master can see it.
How to deal with it?
If you see water vapor forming on the bottom of the headlight but the top is still very clean, then it is generally a normal situation of fogging. It is recommended to put some desiccant in it and turn on the headlight frequently to dry out the moisture inside. The water vapor usually dissipates in about a week.
For cleaning work in the engine compartment, you should wipe it with cotton or cloth, or use high-pressure air blowing to avoid "moisture" in the engine part as much as possible.
If the water accumulation inside the headlight is serious, it is necessary to disassemble it and open the lamp cover. After drying, check whether there is any damage or possible leakage on the surface of the headlight. If there is no abnormality, it is recommended to replace the headlight. Cover seal and breather tube.
In winter and rainy seasons, it is recommended to develop the habit of regularly checking vehicle lights, especially after the vehicle has been waded into water. Remedy early and nip the fault in its bud in a timely manner, which is the best choice for car maintenance.
