Under the drivers side A-Pillar cover there's a Yellow wire.. Not sure if it's power for the sunroof or the mirror, but it's 12V switched.. I've got my Siriusreceiver wired to it..

To keep from over drawing to much current on that circuit, you may want to use that to switchON a CONSTANT DUTY relay and get the REAL power from the red ACCS B+ wire that will be above the driver's right foot.. It will be bundled with a blue wire that says something about Trailer and a black ground wire..

 

Thanks for all the help with this install. I used a mini fuse from the fuse block under the hood on #18. this is power ON only when the key is turned on. This worked great and will not void warranty. again, thanks for all the help, HUMMER1