Locating 12V ignition wire

I have a new 2005 Envoy Denali that I have added a DVD player and LCD flip down for the rear seats. When installing, I found a wire on the smaller of the two harnesses connected to the Bose 6 disc changer that seemed to be the 12V ignition sense wire. My volt meter confirmed that the green/black ( I think black) went to 12v when the ignition was in ACC or on. However, I now find that the wire I tapped is switched to the gear shifter and when the car is in gear, the 12V drops back to 0 and the player turns off. I assume that the green wire is for the navigational unit to disable the features when the vehicle is in gear.

Where can I tap a 12V ACC line and what color is the wire? I have searched extensively and have seen many threads about a pink wire, but the pink on the larger wire harness is not 12V but looks to be a data bus (don’t have a scope to verify).

Off subject topic, but I have been reading the threads about the navigation replacement for the 6 disc Bose. I have one on order from the dealer as part of the condition of buying the car. They were more than happy to order one for me (including the DVD and antenna). They are also doing a search for a refurb unit from some of their aftermarket suppliers. I will post some specifics after I get the unit installed for anyone interested.

Great forum. Thanks for any help.