Water on drivers floor board

[bones30]

Hey,

2003 gmc 1500hd

Noticed my floor board on my drivers seat was wet a few months ago. Tried tracking where the water is coming from with no luck. Sat in the truck while I had someone spray water on it. Best I could tell was it was coming from the drivers door seal so I replaced that. Door closes much tighter now, almost too tight but it still has the leak. 
Checked the third brake light. Looked dry. 
My only other thoughts are get the windshield resealed or the trim at the top, back of the cab looks brittle and kind of cracking. Maybe that could be the source???
Any thoughts or advice would appreciated. 
Thanks in advance!

[David03gmc]

Mine's doing the same thing on the passenger front seat floor at the outside edge of the carpet. I just had the windshield replaced but see no sign of water from the windshield. I even put a towel on the floor to catch any water draining to the floorboard but it's dry as a bone. Any help is appreciated.

[bones30]

Water leaks are no fun. 
I have been watching YouTube videos for ideas. 
I’m wondering about the plastic pieces on the roof at the back of cap or maybe the cab vents at the back of cab but who knows. 
I’m grabbing at straws at this point. 

[KARNUT]

A year ago when I bought my Avalanche little did I know water leaking was a common issue. The first time was bad. It was a garage kept vehicle. Probably never driven in the rain. I sealed the sun roof. Bought a little fan to dry it out. The next time it rained it was better but still leaked some. I sealed the removable panel behind the back set. The bed covers leaked too. The little fan is a life saver. Keeps the mold and stink away. By mid summer with sometimes twice weekly visits to my car wash. Along with three times a week vacuum carpets. It’s like it never happened. The leaking stoped. Probably clogged drains the car wash help open. I learned the moving air across the wet area will dry it out pretty quickly. And the smell will stay away.


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[Denali21]

On 2/20/2021 at 6:54 PM, bones30 said:

Hey,

2003 gmc 1500hd

Noticed my floor board on my drivers seat was wet a few months ago. Tried tracking where the water is coming from with no luck. Sat in the truck while I had someone spray water on it. Best I could tell was it was coming from the drivers door seal so I replaced that. Door closes much tighter now, almost too tight but it still has the leak. 
Checked the third brake light. Looked dry. 
My only other thoughts are get the windshield resealed or the trim at the top, back of the cab looks brittle and kind of cracking. Maybe that could be the source???
Any thoughts or advice would appreciated. 
Thanks in advance!

I just discovered the same problem on my 2000.  It’s a shame I didn’t find it until it rotted out my rocker panel.  Like you, I replaced the windshield.  It didn’t fix it.  Tried replacing the door seal.  That didn’t work either.  I finally took it to my brother in law who’s a great body repair guy.  He opened the drivers door and gently poured water from a pitcher on the roof at the door seam.  Sure enough, it was leaking along the front of the door jam seal.  It was running out the bottom of the seal and onto the floor (under the carpet) and under the rocker cover.  It was impossible to see unless the drivers side door was open.  The final fix was that he put some goop behind the seal called strip caulk, and sure enough, no more leaf.  It may not be your issue but it worked for me.  Good Luke.

[davester]

For my truck, water came in the door hinges, which had been replaced (originals are welded on, so they can't leak, replacements bolt on).

[bones30]

Thanks for all the reply’s.
Still on the hunt.

May just put it back together and have a leak or possibly take it to a body shop. 

[bones30]

Just for anyone with issues like this in the future. I now believe it is the window sweep and/or the vapor barrier on the door. My window sweep is old and kinda mildew covered. My vapor barrier is barely hanging on after a few window motor swaps. 
Course of action is new window sweeps and re-securing vapor barrier with butyl tape on the full perimeter. 
I will post my results in a few weeks. 
That or I may know of a nice 03 1500hd for sale. Only viewable during summer months haha jk.