Thank you, yes I have the mirror. (2012 Avalanche) I ended up tapping into the white wire on the mirror. I removed the overhead unit (with the maps lights) and found the same white mirror. I spliced into it and ran the wire down to the HU. Seems to be working fine. Thanks for the help
Where you able to figure out which wire is for the video feed? I also have the feed to the mirror (OEM) but would like to send the signal to the new HU I am installing. Anyone know? A picture would be outstanding. Thx