I have watched every video with what appears to be several different locations of the drain ends.. I Can Not find where that driver side tube ends. It is not under the cowl, not going to the floor, and not under the dash as shown on some..
I removed the Instrument Cluster which is of no help as there is a solid plastic housing behind that.. I see the tube running down the A pillar, and it disappears behind the dash..Any help?
2003 H2 -

 

Down the A pillar nearly a 90 degree bend along the firewall well behind the dash structure, and another 90 degree bend draining under the cowling. You will not be able to get to it. My recommendation to clean it out is water and high pressure air. Reference: https://www.hummerforums.com/forum/h...xits-h2-33827/

 

Thanks..

 

JW how sure are you that it is the sunroof that is clogged? Does it hold water in the tray?

 

ilillnc - I have been chasing this over 7 years off and on. The 2003 H2 drains.. The Driver side is clogged and not coming free this time..
I use a vacuum and air blown in to clear both previously. This time we are not able to clear that side, it holds water in the tray, when the passenger side drains.

Now, of course we have a phantom draw on the battery as well which could be from this water getting in. Who knows..
About to scrap this baby....ugh

 

Go ahead and pull the fuse for the Onstar if that is still in place, they were well known for going faulty and draining the battery from early on. Your going to have to dive in if your sure on the sunroof.


I *Think* I finally found my passenger side leak after 5 years, I had to remove the entire pass side roof rail and found tiny hair line cracks in the body seam sealer just above the windshield that the pass side roof rail concealed.

There is a lot of possible leak locations but you have to just dive in and go.

I find it hard to believe that the exit cannot be accessed, sounds like they built the truck around the sunroof drains.