what wire for 12v accessory on 2011 silverado
 

Does anyone know which wire on my radio harness will work for the 12 volt accessory? I read somewhere that the dark green is it but that doesn't seem to work. I checked at the amp end of the harness and seem to have power there but it won't turn on I think because the account wire isn't working. I think I have the X1 factory radio and am using the fast 9999 and btah extension.