2006 Highlander Nav. problems

Bought my daughter an '06 Highlander limited for college. It has the navigation unit but when I press the map button I get the infamous external device not connected message. Done some searching and didnt come up with any real definitive solutions. I tried to eject the dvd from under the seat and either there's no dvd or the unit has no power. I'm thinking there's no power, which is causing my problem.

Anybody know which wires are the power wires? I have a meter and a schematic for the Highlander, but wanted to ask the question before I start probing with my meter to see if what I find (if there even is power getting to unit) is right.

Thanks for any help guys.