Are the interior lights suppose to illuminate when you open the rear back door? They do when all the other doors are open....

Also,

just bought this Hummer Forums - Enthusiast Forum for Hummer Owners - LittleWhiteHummer's Album: Garage - Her Beast

Was this previously a members?

 

Yes they do come on when the rear door is opened.
Check the door switch. It may be stuck closed.

 

I am having this same problem on my 06. It doesn't activate the interior lights or show that a door is opened on the dash. Where is the switch located to check?

 

After a little bit of research I found the problem. It's the door jamb sensor located next to the right tail light. It's a $7 purchase on amazon and it is an easy install; 1 torx screw and plugging the wireing harness in.

https://drive.google.com/open?id=0Bw...DN0RTdsNjlKclU
ACDelco D6075A GM Original Equipment Door Jamb Switch https://www.amazon.com/dp/B0016HPWCM..._jYjMybWG3HRQA

 

I did order a new switch, i took a look at mine and it seems corroded. Will update after the install...

 

Yeah, they are not the best design. They can "freeze" closed causing the lights not to come on when the door is open or not make any contact at all and the interior lights will not turn off.
I have replaced so many I have lost count. I always have at least 2 spares in the HUMMER parts bin just in case.

 

I replaced the switch and now it works great, thanks guys....