Moisture In Running Lights

Hello all,

I have a constant issue with moisture (water vapor) inside all but one of my camper running lights. I have contacted Camp inn and tried to apply some fixes. They thought that the screws I had were just a hair too long and when screwing them the base of that screw would hit the light bulb housing itself preventing the lens from properly seating on the gasket. I did modify the screws but the lens sits no differently on the gaskets. I can see that there is some compression but not a nice firm compression. I think the “Z” bracket is the limiting factor.

In any case I took the fix a little further by adding a bead of silicone sealant around the lens before screwing it on to the gasket. ( this was another recommendation by Cary and Camp Inn). Now I think I have a nice water tight seal. But time will tell..

My camper is stored outside usually under the custom cover so it is subject to all year weather.

I guess what my question is this... do any of you have any moisture and or water vapor (condensation) in your running lights? If so I’d be happy to hear how you dealt with them..

Seems if that “Z” bracket were a little shorter or the gasket just a tad thicker I’d have a proper mechanical seal.

 

I have the same problem right after it rains, I will try silicone myself as well

 

Have had moisture only in the left rear marker light, after about 16K miles. By the time I noticed it, the bulb was rusted to the bulb holder bracket. I got a replacement unit from Necedah (although it's pretty common and available lots of other places, too). When I went to swap them out, I noticed that the old unit had a wire running across the gasket that breached the seal's design - might have been noticeable during the build; maybe not. Reinstalled with a bead of silcone between the gasket and the trailer wall, and things have been fine since.

Note, be judicious with the silicone. There's a couple of weep holes in the gasket where it mates with the lens and sealing those might be counterproductive.

 

I thought about those “weep” gaps but sealed anyway... I probably should have sealed all my lights on a cool dry day. The day I did it was hot and a little humid so I may have inadvertently trapped humid air in all my marker lights. So far I have only seen moisture in one of them after sealing. But still needs some time to confirm the silicone seal took care of the issue.

 

Oh and also.. I read you sealed the gasket against the trailer wall... so you didn’t seal the lens to the gasket? Was this to make it easier to remove when replacing bulbs?

 

No, although that's also a consideration now that you mention it. Wish I could remember in greater detail how I figured this out, but it was obvious to me at the time that the moisture had gotten in from behind the gasket, not between the gasket and the lens. And those weep holes pretty clearly indicated that it wasn't supposed to be sealed tight on that side.