I have a leak in my sunroof* never leaked before* A small black piece Cracked off opening the sunroof one day. I didn't think anything of it the sunroof still closed. 1year later, it Caused my electrical system to shut down, NO power. Figured that Out from reading your Hummer site* Got that fixed* How do I fix sunroof without replacing it any suggestions of any kind of seal* If I don't fix it It will continue to cause problems* I Hav 2007 H3

 

Pic of missing piece on sunroof would help. Are your sunroof drains clogged?
Have you experienced bcm water damage? Did you have a sunroof drain hose come loose?

 

the rubber seal needs maintenance like anything else. to minimize leaking, not stop it, i clean the mating surfaces 3 times a year with a rag and silicone GREASE. it keeps the rubber soft and helps with leaking. in 7 years i never needed to clean drains. i never leave it open except when rolling down the road,not sitting still where it can collect debris!

 

From here out, please avoid duplicate posts. Just because you did not get a response immediately is NOT a reason to ask the same question again.

Patience weed hopper.