Check your rpo codes inside your glovebox. Then read the first page of the tsb again.

Models with RPO CF5 sunroof

That's the sunroof in my H3

 

Why does that document say there is no drain tube system? Obviously there is because I've done a bunch of work on mine.

 

I pulled the tsb from identifix, obviously there is an error on the drain tube system as the H3 has it. Regardless,
CF5 = ROOF,SUN,GLASS SLIDING,ELECTRIC
and can be resealed to avoid water intrusion.
I didn't reseal my sunroof, not needed after I https://www.hummerforums.com/forum/h...n-tubes-28548/ almost 2 years ago.
However, the op will NOT follow the advice given previously, so I decided to add the tsb.

 

Your advise was/is very helpful, and appreciated. For some months I have been hearing the wind noise you talk about, and since that noise wasn't there previously, I bet the problem may be solved as suggested. I will follow instructions and keep you informed of the results.
Thanks to all of you.

 

what am i missing in the tsb??. i cant find anything relating to my h3??

its for a different vehicle huh?

 

I dont know about the other info is good or not. Sorry I didn't read it all, but no doubt if the seal was adhered to the glass it would be better.
But I would like to note the op said the water could be coming in between the dash and the seat?? Is it soaking your seat? If so it is definitely plugged drains or disconnected is a possibility as well.
If it is just soaking your carpet then your grommet that goes out through the firewall is unhooked allowing all the water to come out the drain inside the dash area which is BAD!! And would be an open hole there which could cause a whistle too I suppose.
You dont need to read all the thread that is above but there is a lot of good info which Will probably help you fix the leak. Even if you want the tsb route you should at least have nothing coming in the cab until you do it.

 

It is soaking the carpet, not the seat; but it is not coming from the dash.
Instead, it is as if it was coming from the bottom of the wall.

 

Sounds like a carpet removal may be in your future. Really it is not very difficult, takes about an hour. Disconnect any couplers under seats and four bolts each, carefully remove from vehicle. Center console is one hex head at back of shifter, then open storage compartment and pull off top part of center console held on by pressure clips (can be a little stubborn). Now remove two screws in front, two screws going down into floor and nut in center and remove console. Now pull off six plastic garnishes along the bottom, first two are long step garnishes that run on each side by the seats. Then second two are up by driver and passenger foot area. Finally remove garnishes on the bottom of the center pillars in the middle of the doors. Lift rear seats up and there are only three nuts holding them to the floor under some rubber caps, remove these. You will have to JUST LOOSEN the bolts holding the seat backs to the floor to slip the carpet out from under the brackets. OPTIONAL - There is a bracket in front of the shifter held down by two nuts you can remove to make it easier to get carpet out but not necessary. Now get carpet loose and fold it is half left over right and slip it out a right side door, (easiest with a helping hand). It is very hard to dry the carpet in the vehicle since there is sponge like material underneath. Now with carpet out and lower garnishes off, put seats back in and do water tests with bare floor. MUCH easier to detect where leak is coming from and no soaked carpet while you are finding leaks. It could be one of several grommets in the floor/side area. Or a door seal is loose/degraded. Good luck.

 

It sounds like you have an AC drain tube clogged...did the same thing on my Nissan pick up...take a corner too hard and water would slosh onto the carpet...I'm still new, 2 weeks, to the Hummer but I bet if you find the drain tube you can poke a wire coat hanger up there to clear the block...