Even if you are the type of driver who cleans and waxes their vehicle on a regular basis, you may have to worry about condensation in your vehicle’s headlights through no fault of your own. So, what can cause this moisture accumulation and how can it be removed?
In this guide, we are going to cover a few causes that lead to condensation (moisture) in your headlights.
Additionally, we will guide you through the removal steps and show you how to distinguish between condensation and water ingress.
Finally, we will offer tips for prevention and answer the most asked questions regarding headlight condensation.
What Causes Condensation in Headlights?
Almost all car headlights are going to generate some type of heat. Some types generate far more heat than others, like traditional halogen headlight bulbs.
Since heat is being generated, there must be some form of venting to make sure the working temperature is normal.
Headlights have designed venting as a method to dissipate heat, but with that venting, it allows for some amount of moisture to sneak into the assembly as well.
If moisture had entered into the assembly the internals of the lamp are designed to absorb that moisture, as long as the lamps are on.
Even with that said, the lens outside of the assembly is going to be cooler than the inside, which is why moisture sticks to the lens. This is what causes headlight condensation.
The reason that thermal convection occurs is that warmer air travels up and that cooler air travels down, which is where the two will meet and condensation occurs. Unfortunately, many vehicles and drivers have to deal with this intermittently occurring on the headlight lens.
How to Remove Condensation in Headlights?
If condensation or fog came from the lens of the headlight, try turning on the lights, first. You might find it evaporates away. You could also use a can of compressed air to clean headlight vents, or a hair dryer to remove moisture.
If the headlight housing is defective, the solution may be to replace the headlight housing so the headlight will seal properly.
There is a detailed explanation of how to remove condensation or moisture from your headlights below.
#1. Wait it Out.
Weather conditions will take care of the moisture, and designers are aware that condensation happens, and it is expected and normal.
Indeed, as a matter of fact, the auto makers such as Hyundai have issued service bulletins that direct technicians to not interfere with normal headlight condensation.
Turn the lights on let the heat do the work, and before long the moisture should dissipate and you will have clear vision again…if you have LED bulbs it may not work, as well as you would hope
But you can also achieve similar results with parking in the sun, just be cautious of the UV rays causing the lenses to discolor over time, and sunlight damaging the cars paint and interior.
#2. Compressed Air.
If you block the vent in the headlight assembly, the moisture will not be able to escape your headlight. No reason to panic, this is an easy fix with compressed air.
You can try to blow out the blockage in the vents with compressed air. Use caution with this solution as you can also push dirt and debris into the headlight housing instead of loosening it.
#3. Hair Dryer.
If the moisture is bad, you may need more power to solve the problem. Take your time removing, and with caution, the headlight assembly to avoid breaking the seal.
Using a hair dryer, you can manually dry out each assembly part. While using a hair dryer, be cautious with how much heat is introduced to each part.
If it gets too hot, there are some electrical components that can melt, such as the wiring. Additionally, it can damage the rubber or lens. That’s why you don’t want the hair dryer to reach higher than 180 degrees Fahrenheit.
Once you have dryed the moisture out of the headlight you can now go through the next step to ensure the headlight is sealed with the exception of the valve and drain hole. If you don’t, moisture will become an issue again.
#4. Fix or Replace Headlight Assembly.
If you’ve tried the other methods, and the issue persists, it may be time to replace or repair the headlight assembly. The headlight assembly is likely defective to some degree, resulting in moisture intrusion.
The already defective headlight assembly could have a crack, or the rubber gasket could be damaged. In either case, the assembly will allow more water into the headlight than it was intended to hold.
Pricing replacement options for the assembly is a good idea. If the assembly is still pricey and you only need a new rubber gasket, go that route. If the assembly has cracks, spend the money for a new one.
Condensation vs. Water Ingress
If you’ve noticed some moisture in the headlights, it’s important to discern if it’s normal condensation or water ingress. After you understand this, you will know how to approach the problem.
Typically, headlight condensation occurs when water vapor condenses from a gas to a liquid and will show up as fogging, misting or small moisture droplets in the light lens.
As condensation is normal, this should never affect the operation of the light. It should usually evaporate on its own and lead to zero additional issues.
This is not the case for water ingress. When water leaks into the light and collects, this is worse than condensation.
The ingress indicates there is damage to the headlight assembly that allows water into it. Once water is inside the assembly, it cannot evaporate normally and will accumulate and pool.
If the headlight assembly is covered by warranty, you may be able to replace it for free through the warranty due to the defect. Otherwise, you will need to replace it to minimize the chances of causing further damage to the headlight or electrical components attached.
Preventing Moisture in Headlights
#1. Check Headlights Regularly.
Occasional condensation may occur, which is expected, but you can lessen water from getting inside by routinely checking your headlights. If you notice dirt and debris clogging the drain holes, water cannot escape and will start to build up in the assembly.
If there is a compromised seal in your headlight assembly, you can fix the seal before water enters the headlight assembly.
If the lens or housing are cracked, replace it.
#2. Use Headlights.
Using your headlights at times will help reduce moisture build up in your headlights. The heat from the bulbs evaporates any condensation it hits.
Even if you do not drive at night, turn on your headlights at times during the day and leave them on.
Occasionally you may park in the sun, however, that will exist longer than three hours and can ultimately produce UV damage on headlight lenses, body panels, or materials in the car.
#3. Create Strong Seal.
To prevent water from entering, the headlight assembly should have a strong seal. Fortunately, there are good sealant products that help you create this bond. After a little research, you will find that the process is easy to get a seal in place.
- Carefully remove the headlight assembly.
- Check the existing seal for debris or damage.
- Simply remove any loose debris.
- Make a bead of sealant along the factory seal to keep the moisture out.
- If the seal is broken, you may have to replace it entirely.
- Now you want to put the headlight assembly back into place. Be sure to check the angle, and make sure you reconnect everything the way it was connected when you removed it.
- Now test the light to see if it is shining normally.
- Now check the housing for any moisture problems to see if it has changed.
While doing this, be sure to check the O-rings that are surrounding the bulb, vents or electrical connectors.
If the O-rings are broken, you want to replace them so water does not infiltrate deeper into the light. We also recommend a sealant gel if you can locate any small cracks in between the housing and the lens.
Will Headlight Condensation Eventually Go Away?
When the headlight is functioning properly the water should drain by itself and the condensation will burn off when the light is on.
There are some light bulbs which do not produce heat as much (like LEDs), so this may take a little longer until the sun will burn off the moisture.
Is Headlight Condensation Damaging?
The condensation we discussed in the previous section does not effect the headlights externals functional use as you will not see any significant difference in the performance and most all reflectors come pre-treated with a insulator spray to prevent performance deterioration and rusting.
But the only potential damage can occur if the seals inside the assembly are damaged and water can get into the electrical parts and this could become a bigger problem.
Is WD-40 Good for Cleaning Foggy Headlights?
Most household have a can of WD-40 lying around for different odd jobs when you need to fix something.
If it’s foggy headlights you’re dealing with well, you may think this multi-purpose lubricant can clean them all right enough. Although it is the best cleaner it probably will be just enough for you to get by in a jam.
Does Vinegar Damage Headlights?
Vinegar is a great cleaner that can be used on headlights. It has good reviews about removing discoloration and fogging on headlights.
It will also take away grime and dirt that has built up on the lens over time until the lens turns yellow or hazy, you may even mix a little baking soda with the vinegar to create a more powerful solution to whole solution.
Can a Magic Eraser Clean Foggy Headlights?
A Magic Eraser should never be used on the paint of your vehicle because it will cause damage down the road, but it has always been safe to use on clouded/tinted headlights. It will also get rid of the yellow discoloration that often comes after time.
Gently buff each lens after you wet the Magic Eraser then wipe off with a paper towel before letting it air dry completely from moisture.
Conclusion
Moisture will sometimes dry out on its own. If you want to take action, you can try some compressed air or with a hair dryer. You will also want to make sure that the headlights will be sealed.
If nothing seems to work, you may want to consider replacing the entire headlight with a new one, especially if you are having moisture enter the lens cover.
It can look ugly to see condensation coverage behind your headlight, especially when you are proud of your car’s glare.
Not only would you want to check your headlight at that time to make sure there were not any issues for down the road, but you should also be glad you caught it now than later when it’s fully developed.
With a good amount of condensation in your headlights, it may take care of itself, but it’s always better to be the person that took initiative for crystal-clear concerns.