Look under the dash on drivers side there might be a small amp there. There was on my 91 740. You have cut wires at amp a re-splice them. Of course this is if put an aftermarket deck in there. If not and you are still using facory deck, you will notice that one side of amp has a special plug that goes to deck and the other has the speker wires. Check and see if any of the wire match the ones you hooked up in the door. Hope this helps, Shawn.