I bought these rear lights and noticed yesterday condensation in one of them. I only have thirty days to return them, so I’ve been watching them.

What causes this? I don’t notice any water in there.

 

Years ago I had the similar on a different vehicle. I drilled a really small hole, 1/16” or so, in the top and bottom of the housing lens assy. One on the bottom to let excess moisture drain out, one on the top to let moisture vapors escape. Drill in a inconspicuous spot.

i think the root problem is that the housing is not completely a sealed air/water tight.

 

Thanks for that idea.

I also wonder if there's a way to create an airtight seal. I'll peruse YouTube.

 

Put some silica packs in there if you can. Will absorb the moisture.

 

The moisture is “trapped” between the outer clear lense and internal bulb cavities

 

Throw a bead of silicone around the perimeter to help seal. Also make sure the bulbs are nice and tight.

 

Its due to temperature, and your exhaust is right below the lens.