Leaky license plate light assembly

Water is leaking into my license plate light assembly even though the two lenses on the top have been sealed with a very small amount of clear silicone. Also, I've been using dielectric silicone grease between the assembly and the rubber gasket just in case it was leaking there. Add to that that the car was just standing still when it rained, I didn't drive it in the rain. Something similar is happening with my left tailight assembly. I'm at the end of my rope here, could water be getting in by osmosis?....

more silicone

Ricardo, how much water? Are you sure it isn't coming from condensation caused by the cold rain water on the surface and the warm humid are inside the unit condensing. Or is it too much water to be that?

Well Steve; all I know is that if it's condensing it looks like it's seriously condensing in there; a lot of water on the reverse light lens and some on the license plate light lenses. I've cleaned the assemblies thoroughly and tried to seal them; it seems that as Bruce says I'll need to put more clear silicone in there. Have you experienced similar problems?

I would think about prying the whole assembly off the car and drilling some TINY holes maybe 4 per side ON THE BOTTOM to let it breath. We touched on this B4 and I am still thinking you are having a humid issue. The smallest bit you got just to let it breath.

That's a good idea; maybe the holes could not only let it breathe but drain too. Have any of you with a VS in humid climates or otherwise experienced the same thing?

No offense intended, but that's a bad idea - the light fixtures must be water tight, otherwise you'll have corrosion problems.
I fabricated lights for my boat trailer that were absolutely water tight - even being submerged in salt water.
Getting a good seal is not that hard to do - replace all the seals on the lights.
The seal around the SU light can be sealed with some black or clear silicone - apply masking tape around the rubber seal leaving a ~1/16" space between the rubber seal and the metal - apply the silicone, then remove the tape before it cures.
I ordered new seals for my tail lights and SU light (from parts obsolete) - the SU light seal is a better quality of rubber that the one that came with the original unit.
Another suggestion would be to make sure the small screws (or bolts?) that hold the plastic lenses on the SU light are sealed as well.

He is in San Juan, he's going to have corrosion problems no matter what he does....if the water is pooling up inside I would drill the drain/vent hole. I guess it depends on how much water were talking about?

Steve, I checked today and I've got some condensation inside the left tailight lens and a lot of it inside the SU light; on all three lenses.

take a water hose to your problem areas and see if it fills up??? if it does then you know it is a leak, if it doesn't or only a tiny little bit then you know its just condesation. My car would get about a 1/4 inch of water from condensation. It only happened once in a while when the weather was very humid and hot and the car got rained on from a thunderstorm....very cold water. I figured out it was condensation, because the water hose didn't add water no matter what I did?

R.B:

See my other post on this, but bear in mind that those Asian light assembly gaskets seem to dry out, crack and get porous in a relatively short time, especially if they're left outside in bright Summer Sun. Just poor quality rubber, I guess........

I tried rubbing black silicon caulk into mine, but I can't honestly say whether it worked or not.......I wonder if something like Armor-All would help delay the drying out?? Haven't tried it, but curious......

Yes Gord; I read your pointer on "restoring" cracked rubber with black RTV; seems like a good and logical idea. I'll definitely work on that and a couple of other small items this weekend. The other day I was cruising on a new expressway near Roosevelt Roads Air Force Base in Ceiba (eastern part of the island); it was beautiful out with almost no traffic, just wonderful and very rare here....

Took out the license plate and there was enough water inside to form a small puddle of water when I removed the assembly from the car. The left tailight lens wasn't so bad. I will test the SU light with a small amount of water to see where it's leaking. If it's not I know the water is seeping in between the assembly and the rubber so I'll put silicone around the full perimeter of the assembly using masking tape as suggested by David.

Water is definitely leaking between the rubber and the SU light. The stuff I sealed before is watertight.

Did exactly as you guys suggested and sealed the whole thing, including tailight lenses with silicone; thankfully I did a clean job so no one can't tell. Regarding the SU light I noticed something that maybe is causing the leakage. The rubber seal has a small hole in the center through which the wiring passes. I guess if the rubber to body seal isn't good enough, water can seep in between them , into the wires and then into the SU light. I put a big blob of silicone there too to prevent it from happening. I hope I've solved the problem for good; that is, until I need to replace a bulb.....

Now that you've got it all glued shut, I've got a trick for you when you DO change a bulb.

Once you've got it apart and cleaned up and ready to go back together, run a bead of the clear (or black) silicon caulk where you want it. Don't make the bead too big - 1/8" or so is good. Then, walk away for 15 - 20 minutes so the caulk has a chance to partially cure or "skin", then put everything together. It should seal just as well, and should also come apart more easily in the (hopefully, distant) future.

That blob around the wire port is a good idea, too......

Great idea! Never though about letting it "skin" a little. Makes sense since contact cement works the same way....

Update; I was under pouring rain today since I was doing some errands in the car. There's not the slightest sign of water inside either the SU light or tailight lenses. We can definitely conclude that the water leaks in the SU light between the body seal and the SU light itself. With regards to the tailights, water leaks in between the chrome surrounds and the rubber seals.

With regards to the interior...well, that's another story...it was drenched.....