2014 GMC Sierra 1500 shark fin water leak

[Double D]

Hello people,
New to this site and am in need of any info regarding water leaking from the shark fin antenna on my '14 GMC Sierra double cab. My understanding is that there is an internal circular gasket at the base (once removed from roof) that actually seals out water....NOT the black piece of molding with the vent gap/slit at the rear. Am I correct in my assumption ?? The dealer I bought it from is aware of this leak, but I'm afraid that they may just get on the roof and slather a bunch of silicone sealant around the base of the antenna, thus plugging up the air vent hole, rather than dropping the headliner some, removing the antenna,and replacing the smaller gasket inside the base of it. Any help would be appreciated ! Why does there need to even have a air vent in the mounting molding anyway? Seems to me its just an invite for water to pool up inside. Is there a drain in the roof somewhere for any pooled water to escape ??

 

[mogleybear]

I think typically if you have a sunroof there are drains for the roof. If you don't have the sunroof I don't think that there are drains, the theory being the roof has no penetrations for water to get into that aren't well sealed. I can't tell you whether or not there is a smaller gasket underneath the fin antenna since I don't have one. I understand your concern with the dealer, you could always tell them that it will not be an acceptable form of repair for the leak prior to the work.

 

[Double D]

Thanx Mogleybear,
No sunroof in my 2014 Sierra, so that's not an issue. And yes, there is a small somewhat circular shaped gasket/seal under the shark-fin antenna. This is where the water is leaking I believe (I googled it) and then dripping from the pass side of the overhead console. It goes in today for repair.....hopefully they will have the where-with-all today to drop the headliner and replace that seal properly rather than just goop silicone around the antenna on the roof !! We shall see.
Oh, on another symptom.....ever heard of the heated cushion portions of the heated seats not working (both sides)? The backrest portions of both seats heat just fine, but the seat cushions don't heat up. It has separate switches on each to select either seat heat OR both seat AND backrest heat together. The indicators show that they are working, but they don't. If it were a blown fuse, I wouldn't think the seats would heat at all, but sure would like to know where the problem lies. Any help would be great. Thanx again.

 

[mogleybear]

Sorry, I can't help you with the seats. The last GMC I had with heated seats was a 2003 Sierra Denali. Never had an issue with the heated seats on that one. My 2012 doesn't have heated seats (well, factory anyway).