Find the wiring diagram somwhere online for the specific head unit and find out what need to plug into what from the car. In order to make it work Power should usually be red and ground is usually black.
Try finding a different power/ground wires in the car. I would try and tap into the existing harness for the stock deck, AND what you should do is just buy an adapter for the new head unit to plug right into the stock decks harness. OR if you dont know what your doing then dont mess with the wires, becuase if you dont make it work the girl wont like you
