Shark fin or brake light leak???

Went behind my rear passenger seat today to get my jump starter out and found it wet along with a rusty speed wrench......hadn't noticed this ever before (bought truck used in August of '17). Paperwork in case and a second case were soaked and moldy.

How can I check to find which is the likely culprit for the leak?? Drivers side was dry as a bone.

Is it easy to check under the carpet for moisture - rust?? I mean, is it easy to lift carpet near the rear seat??

Did a search on this prior to asking, but read too many posts that weren't answering my questions.

Lastly, would a leak at either spot be covered under warranty?? Got my 35,000 service coming up and truck was made/ordered in January of '16.

THANKS guys!!!

 

Probably the 3rd brake light. Bring it in! Covered under warranty. Toyota has actually had to buy back a few because of mold.
Just realized who you were. You ever paint the end caps?

 

You’re covered until 3/36k so better get it in ASAP

 

Yeah, gonna call for an appt next week. Tomorrow I am going to see if the floor is wet as best as I can. Thanks again, guys!

No haven't done the end caps yet, but I am planning on doing them black eventually.

 

Brake light.

 

Another thread on this in less than 24 hours. Might need to go check mine here after this storm.

 

Went out yesterday and checked the interior....carpet was dry, seats (front/back dry), then looked at the headliner: 4-5" wide water stain across the top of the rear window from one side to the other.

Will be calling dealer tomorrow or Tuesday.

 

Went to the dealer today for 35,000 mile service......all checks out okay. Checked a couple of recalls with no issues. Total cost was under $17 for the tire rotation.
Said it was the 3rd brake light leaking and had to order a new light - return next Tuesday to have it fixed. No questions/hassle from them at all. Didn't think to ask what they will actually do with the headliner - water stained. They are giving me a loaner for the entire day, so from the sounds of it they are going to thoroughly check things out, not just change the light.

 

got a new third brake light/gasket installed today.......should be good to go. Unfortunately, I forgot to ask about the stained headliner.......anyone got a good/easy way to get the water stain(s) cleaned off???