Last Updated on July 30, 2021
Maybe you just got back from your state’s motor vehicle inspection and need to figure out how to get the moisture out of your headlight assembly to pass your inspection. Or perhaps you noticed you can’t see as well at night as you need to.
Either way, excessive moisture in the headlight assembly is a big deal. Determining how the moisture is getting there plays a significant role in what you need to do to get it out, which is why we dove into every potential cause and solution here.
Don’t worry, you’ll get your headlights dried out and your vehicle back on the road in no time!
Read Also: HID vs LED vs Laser Headlight Comparison
What Causes Moisture to Get in a Headlight?
There are three significant causes of moisture inside of your headlight. Any of these can also apply to other exterior lights such as fog lights, tail lights, and side markers.
#1 – Headlight Vent
The second potential cause is a blocked moisture vent. This is the best-case scenario because you won’t need to break the seal and repair the headlight if you do everything right.
A blocked moisture vent causes your headlight to fill with water because as the halogen bulb heats up and cools down, it creates condensation – and without anywhere for that condensation to go, you get moisture in the headlight.
#2 – Headlight Seal
The first is a faulty headlight seal. If this is the case, you’ll need to either repair the seal or replace the headlight.
#3 – Damage to Headlight
Finally, you could have a cracked or damaged headlight assembly. If this is the case, you’ll either need to get creative with repairs or, more likely, you’ll need to replace the headlight assembly.
Is Condensation in the Headlight Assembly Bad?
It definitely can be. There are several reasons condensation in your headlight assembly is bad. For starters, it’s water around electrical components, which is always bad. You can short out the system, corrode wires, and create many problems that will require additional repairs.
Not only that, but condensation in the headlight leads to foggy headlights. When you turn on the headlights, tons of light will get obstructed by the condensation, which means you won’t get as much visibility. It’s not hard to see why this is a big deal.
How to Get Condensation Out of Headlights
If you have condensation in your headlight assembly, you need to get it out. There are a few different ways to do this, and it all depends on how the condensation is getting in and how much condensation is there.
Cracked Headlight Assembly
Let’s start with the worst-case scenario – a cracked headlight assembly. We’re not talking about a faulty seal or blocked vent here, but a full crack. In this case, you’ll need to replace the entire headlight assembly to prevent future water from getting in.
For short-term fixes, you can try using a hairdryer to dry everything out, but it’s going to be hit or miss if this works well enough. But even if it does, the next time there’s morning dew, rain, or any other condensation, you’ll end up right back where you started.
The next problem is a faulty seal. This is a pretty big deal since the seal isn’t a super easy fix most of the time. You need to start by removing the headlight assembly and gently prying the assembly apart at the seal.
Start by drying everything off inside. After that, you’ll need to either get a hot glue gun and run a new bead around the entire assembly, or if you’re lucky, use a seal for the headlight from an auto parts store.
But most headlights don’t have seals like this, so you’ll likely need to do it yourself. You need to get an airtight seal, so take your time and do it right the first time.
Blocked Moisture Vent
The final potential problem is a blocked vent. This allows the condensation that builds up from the changing temperature caused by the bulb to escape. All kinds of debris can block this vent, so check that it’s clear before removing any seals.
If it is, do your best to get the debris out of the headlight instead of pushing it in. If it does get stuck inside the headlight assembly, you’re right back to needing to break the seal to clean everything out.
What If Water Continues to Get in the Headlight?
If water continues to get into your headlight after your repair, chances are you still have a faulty seal or a blocked vent. You can either reattempt repairs or replace the headlight assembly.
While replacing a headlight assembly isn’t always cheap, it’s a better outcome than shorting out the system and starting a fire or losing visibility at night and getting into an accident.
Whatever you do, don’t accept moisture in the headlight assembly. It’s only a matter of time until the minor inconvenience turns into a big problem.