Replace Bulb Sealed Trailer Light: What You Need To Do

Sealed trailer lights are great! They keep out water and corrosion so your bulb can work on your boat trailer or utility trailer. Even many travel trailers now have sealed brakes and tail lights to provide extra weather protection.

But what should you do if your bulb gets burned? I mean, it’s a sealed unit. Is there any way to replace the bulb in a sealed trailer light? The quick answer is that you cannot replace the bulb in a sealer trailer light.

However, there are other things that you can do should you have a burned-out sealed light. This post will review the steps you can take to fix that sealed trailer light, including a step-by-step guide on what you will need to look out for.

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Even if your bulb is not burned out and you want to replace it with sealed LED trailer lights, this post will give you tips and tricks on replacing it.

Sealed Trailer Light

Many trailers now come with sealed lights (this can include running light, tail light assembly, and brake lights). And with good reason, as they have the advantage of keeping out water and protecting the bulb from premature burnout or a wiring issue. But, with that advantage comes a disadvantage: the bulb is designed not to be replaced.

The bulb in the sealed trailer light cannot be replaced.

Even if you decide to break the seal and remove the cover (which I don’t recommend), the bulb itself is not in a socket meant to be replaced. As I removed the clear cover of my sealed trailer light, I came to the realization that the bulb is wired into a plastic housing and does not have the typical bulb socket where you can easily switch out the bulb.

The only real solution to replace your bulb is to replace the entire light assembly.

Replace Trailer Light

You must replace the entire lens assembly if you have a burned-out sealed trailer light, brake light, or marker light. The good news is that many of these lights are available at home centers or even boat stores like West Marine. Here is a quick step-by-step guide to replacing your sealed trailer light.

Step 1: Buy the same size and shape light

Your best option for a new light is to pick out a lens assembly that matches your trailer. Sticking with the same shape and size will be easier to replace as you should not need to modify any brackets or the trailer frame to replace them.

Step 2: Think about replacing with LED trailer lights

If possible, look for the same trailer assembly in an LED light. The LED light will last you about 25,000 hours, whereas an incandescent bulb will only last around 1,000 hours.

Look for LED so you will never need to replace a bulb again.

This is definitely a plus with a sealed trailer light, as you will never need to replace a light bulb again if converting to LED.

Step 3: Check the wire harness

A wiring harness connects sealed trailer lights to reduce the chance of a wiring issue. And to help keep the water away, the lens assembly with have dielectric grease where it plugs into the harness. You may get lucky and find one that matches your current harness.

Get a matching wire harness if you can.

If you can’t find a light that matches your harness, you must cut and connect the trailer wires. Remember, you are trying to keep a water-tight system, so I suggest using waterproof connectors and ensuring no exposed metal is showing on any wire. Using only electrical tape or a twister wire connection will not give you the water protection you will need.  

Step 4: Install the rubber grommet

Since you can’t directly bolt your lens to the trailer frame, you may have a rubber grommet to hold the light in place. Once you remove and replace the light, set the new rubber grommet to your trailer. Ensure it is secured like your old light, and use the same size bolts. 

Next, set the light in the rubber grommet and ensure the trailer light feels secure. If you feel that there is too much wiggle room, you can use clear silicone caulk to keep the light in place.

Final Thoughts

Sealed trailer lights offer excellent protection against water and corrosion, ensuring the longevity and functionality of bulbs on boat trailers, utility trailers, and travel trailers. However, when a light bulb in a sealed trailer light burns out, it cannot be replaced individually. Instead, the entire light assembly needs to be replaced, making it necessary to purchase a matching size and shape assembly. Switching to LED trailer lights can provide longer-lasting performance and eliminate the need for future replacements.