Interior leak

[OceanRescue01]

Any ideas where this could be coming from? Been raining, not really heavy, all day. Truck always smells musty/mildewy after rain. Found the culprit, now just need the fix. Any help appreciated. Pic is of space under the rear seat, driver’s side

 

[NETim]

Cab vents most likely. Could be rear sliding window or maybe the sharkfin antenna. But most likely those cab vents.

 

[1999 White C5 Coupe]

Any ideas where this could be coming from? Been raining, not really heavy, all day. Truck always smells musty/mildewy after rain. Found the culprit, now just need the fix. Any help appreciated. Pic is of space under the rear seat, driver’s side

Also check the gasket on the center, high-mounted brake lamp.

The seal is notorious for leaking and there are many posts on this forum about it. When you remove the lamp assembly, look inside with a flashlight to see if there are water stains or dampness.

 

[Atcer2018]

Can also be more than one place it’s leaking. I pulled my rear seats and replaced the exhaust vents with pride knowing I conquered my leak problem only to have wet carpet the next storm. Third brake light was also leaking. As inconvenient as it may be, removing the rear seats and the back of the cab covering next time it rains will allow you to see where the water is coming from.

 

[NETim]

Also check the gasket on the center, high-mounted brake lamp.

The seal is notorious for leaking and there are many posts on this forum about it. When you remove the lamp assembly, look inside with a flashlight to see if there are water stains or dampness.

Oh man! How could I forgotten the notorious brake light gasket? jeez.

One of the first things I did to my truck was replace that gasket with some proper weatherstripping.

 

[OceanRescue01]

Thanks fellas. I have an aftermarket 3rd brake light so I’m hoping that solved that issue. Guess it’s time to get the ol socket set out and get to work.

 

[SitKneelBend]

Thanks fellas. I have an aftermarket 3rd brake light so I’m hoping that solved that issue. Guess it’s time to get the ol socket set out and get to work.

I'd imagine if the sharkfin or puck antenna were the culprit the headliner would be wet too. I wouldn't rule it out though but in the order I think the culprit might be and ease of accessibility I'd check:

1. 3rd brake light
2. Rear Cab Vents
3. Antenna mounted above rear driver side passenger seat.

 

[Roonie]

Does anyone have the part number for the replacement vents? Local dealer told me this vent was on back order and was not sure when it would be available. Not sure if there is some other source of these vents??

Not looking forward to the seat removal, seems like it is a PITA.

 

[SitKneelBend]

Does anyone have the part number for the replacement vents? Local dealer told me this vent was on back order and was not sure when it would be available. Not sure if there is some other source of these vents??

Not looking forward to the seat removal, seems like it is a PITA.

68323649AB...I looked online, dealer prices seem to be the best and surprisingly cheap for OEM part.

 

[Jas34]

I got mine through a dealer at Worldpartsdirect.com.

Updated cabin vent (exhauster)

It's been mentioned in a previous thread, but thought I'd put up a couple of pics of the newest version of the cabin vents behind the rear seat that tend to leak and leave water in the floor of the under seat storage. First pic is the outside. The new one has a rigid plastic flange outside of...

www.ramforum.com

The seat removal is no big deal, just a few bolts. You can carefully remove and replace the vents from the inside.

While you're at it, check the drains in your sliding window track. They should drain to the outside. Besides the 3rd brake light gasket and the vents, plugged drains in the window track can be a real leak point.