Trunk Moisture Questions

[Sehnsucht]

Hey, so this winter I started getting some moisture buildup in my trunk and interior. Already sorted out the interior issue, but the trunk's leaving me with a few headaches:

Basically there's a bit of water pooled up in the spare jack and battery well areas. The carpet on top of the spare wheel is damp, the trunk wall cover was molded out, but the spare tire well is as dry as a desert. There's a slight bit of moisture around the liscence plate area but not around the tail lights. Luckily this hasn't been happening for long, as there is no rust and the carpet wasn't molded yet. I'm replacing the carpet anyways for other reasons (had a 5gal jug of oil leak in the trunk) but it's good to know it hasn't been sitting like this.

The first thing I assumed was that my sunroof drains are clogged or damaged. My first question is: how can I access these without pulling the headliner? I read about a method on here a while ago but can't seem to find the post again on search.

I'm also guessing my liscence plate lights are rusted out and leaking too, albeit not much. Easy fix. Any other potential sources of leaking from this area?

My tail lights didn't appear to leak anything (carpet surrounding them was dry) but.. If I remember right, isn't there supposed to be a rubber seal between the tail light enclosures and the panel holding the bulbs?

Anything else I should check? On visual inspection, the 3rd brake light and trunk seals appear to be in good condition and the trunk is clear of debris. I'd rather fix any potential leak sources in one go, so I don't end up with any issues down the road.

Are there supposed to be drains in the jack and battery wells? I couldn't find one at all in the jack well, and the only hole I could find in the battery well was the battery acid drain tube plug. Am I just not looking hard enough? It was kind of dark.

Thanks in advance for any answers, I appreciate it.

[ELVA164]

From another thread:

The list, which I believe is complete:

-Antenna seal (replace it either way, it's cheap and worthwhile)
-Trunk gasket (even if it's soft, it may have lost its shape and won't completely seal.)
-Taillight gaskets
-Sunroof drain seals on each side under the rear bumper (these have to be special-ordered if I remember correctly, so plan to wait a couple weeks)
-Make sure the tube for the sunroof drain is completely seated into the side panel itself; over time the hose can dry up and pop out, dumping the water into the area inside the bumper
-Rear window seal

Did you test the drains? Just pour some water in the sunroof (when it won't immediately freeze, heh...) and see if it runs out the bottom. Rear ones drain behind the wheels, fronts drain at the front of the rocker panel. Should be a slow but steady stream. You can access the tubes behind the trunk lining in the rear and by removing the kick panel speakers in the front.

License plate lights may be rusty but aren't a very likely source of leaks.

No rubber seal between the light and the inside panel, just the foam gasket.

No drains in the two wells, they would let water in from tire spray in wet conditions.

[Quadrajet]

Personally I think the biggest culprit, especially since I've never had a moisture problem till this year, is the taillight gaskets or seals. I had to change my RH taillight lense, either I didn't get that seal in correctly or my "new" lense has a crack somewhere.

[Sehnsucht]

From another thread:


Did you test the drains? Just pour some water in the sunroof (when it won't immediately freeze, heh...) and see if it runs out the bottom. Rear ones drain behind the wheels, fronts drain at the front of the rocker panel. Should be a slow but steady stream. You can access the tubes behind the trunk lining in the rear and by removing the kick panel speakers in the front.

License plate lights may be rusty but aren't a very likely source of leaks.

No rubber seal between the light and the inside panel, just the foam gasket.

No drains in the two wells, they would let water in from tire spray in wet conditions.

I haven't tested the drains yet. My friend was detailing the exterior while I worked on the trunk, and I figured not being inside the car shifting my weight around would be a good idea. I'm going to test them out tomorrow, but also clean them anyways while I have the trunk liner out.

I also noticed the antenna seal was a bit crusty looking, that could be a potential source as well.

Personally I think the biggest culprit, especially since I've never had a moisture problem till this year, is the taillight gaskets or seals. I had to change my RH taillight lense, either I didn't get that seal in correctly or my "new" lense has a crack somewhere.

My taillights don't have foam gaskets. I'll order some. One of my lights is slightly cracked, but I don't think it would leak. No condensation on lights, nor is there any moisture on the trunk lining around them, so I think there may be another culprit. But I'll fix it anyways.

Another question: Does the lining on the back of the trunk (nehind the back seats) serve any functional purpose outside of aesthetics? It was moldy so I tossed it.