Need help replacing stock headunit for aftermarket headunit.
 

So my friend has the hyundai xg 350 and its a 2004 we just go the old headunit out of the car and we got everything hooked up the aftermarket is hooked up. Except when we plus the battery back in it powers up just the headunit isnt playing sound through the speakers. We had to attatch the ground wires to the frame but we have one wire that is hanging loose its an orange wire which deals with illumination. Any ideas on why this isnt working this would be very helpful please and thanks!:)

Bump i really need a hand here guys i dont wana go spend 75+ dollars an hour to have some pros do it.