What to Do When the Front Windshield Fog Cannot Be Blown Away?
4 Answers
If the fog on the front windshield cannot be blown away, it may be due to a leak in the glass interlayer seal, allowing water vapor to enter the windshield interlayer. Specific details are as follows: 1. Solution: Identify the leak in the windshield seal, blow out the water vapor from the windshield, and reseal the windshield. 2. Cause of fogging: Fogging on the front windshield can occur on the inside or outside. Whether internal or external, the main reason is that the glass surface temperature is lower than the air temperature, and the air humidity is relatively high. When warm, humid air encounters the cold front windshield, it releases heat and condenses, forming fog.
I've encountered the issue of windshield fogging that won't clear up many times. The key reason is the large temperature difference causing high humidity inside the car. If the air conditioning doesn't help, you should check if it's set correctly. It should be adjusted to the defogging mode, which is the button with a fan symbol, directing airflow straight to the windshield. Additionally, slightly opening the windows for ventilation can quickly reduce humidity, though it's too cold in winter. Always keep a towel handy to wipe the inside of the glass before driving. Also, using a specialized anti-fog spray and wiping it clean can maintain the effect for one or two weeks. Remember to regularly clean the air conditioning filter, as a dirty one can affect dehumidification. If fogging occurs while driving and obstructs vision, don't rush to drive fast; instead, turn on the hazard lights and pull over to deal with it. Unresolved fogging is even more dangerous at night, increasing the risk of accidents. In short, early prevention and regular maintenance are key.
When the front windshield fog won't clear, here's how I usually handle it. Set the AC to AUTO mode - adjusting temperature higher or lower both helps dehumidify, but the key is increasing fan speed directed at the glass. If your car has a dedicated defog button, press it and wait about 30 seconds. If that fails, crack open a window slightly to release moisture. I always keep in-car defogging spray (the aerosol type costs about $10 per bottle) - spray and wipe with a cloth to disperse fog quickly. Remember not to block AC air intakes with debris. More passengers mean more CO2 exhaled, accelerating fog buildup - pull over for fresh air if needed. Regularly check AC refrigerant for leaks; poor cooling performance requires repair. Fog isn't just annoying but dangerous - reduced visibility delays emergency braking. Learning these DIY tricks saves time and money.
When the windshield fogs up, I immediately turn on the air conditioning's dehumidifier mode—the one with the vent arrow pointing at the windshield. If that doesn’t work, I crack open both windows slightly for ventilation. Since my kids often cause heavy fogging in the car, I always pre-wipe the inside of the glass with a slightly damp cloth to reduce condensation. In winter, I keep a bucket of hot water in the car but avoid placing it directly, as it can increase moisture. Replacing a dirty air filter doesn’t cost much. If the fog won’t clear, don’t force driving—find a safe spot to stop and handle it. Heavy fogging is usually due to temperature differences or unsealed food in the car, so avoid leaving leftovers inside. Simple measures can prevent it.
