If I remember right they both exit into the cowl area under the cover. Have to remove the two corner pieces and wipers to remove the main cover (which is a pain and feels like you are going to break it).

 

 

Have you tried running a weed eater line down the tube? If you used too much air pressure, you could have blown the hoses off the fittings.

 

Thanks for the feedback ! I'll give the weed eater line a try. I used a wire that I don't think was flexible enough to get around the bends. It went about 2 feet down, but then got stuck. I kept the air pressure fairly low (25psi), and it seems the connections didn't move.

 

 

Do some more searching on here. Search is at the top right..

https://www.hummerforums.com/forum/h...r-32846/page2/

That one shows the passenger side front drain tube. I thought it was under the cowl. At least it also is on my 2003. Exits right above the fresh air intake. I'm pretty sure the driver side one also exits under the cowl as well. On reading a bit more it runs down the a pillar and pretty much exits into the cowl area almost directly behind the instrument cluster. The rear ones gown down the middle columns and through the floor.

That being said - it might not even be your sunroof drains. That same air intake - there is a cover high above it that can leak and let water drip into the fresh air intake where the fan is. The body seals around where the doors hit can actually allow water to run down to the inside. There are also two rear sunroof drains as well. The metal body seams under the roof rack rails can be defective. Quite good odds the windshield has been replaced (common since ours are so vertical and flat to get damaged) and that could be leaking. Of course any one of the upper clearance lights might be leaking, not just from under the light into the hole but the actual lens could have a tiny crack which I've seen.