Factory video system
 

I recently changed the deck out in my 05 Excursion. I went with the Alpine CDE-9852 and used the wire harness that I bought at
Best Buy. After I left there I was jamming to my new radio with the Ipod hooked up. Last night my son wanted to watch a movie but now I am having problems with the video system. So I brought it back to them and they said that was something that they had to tag into in the second harness that was behind my radio but they could not find in thing on there computer to tell them how. Does anyone out there know of somewhere to look so that I can get this fixed? Or does anyone know how to fix it? Thanks.