I am wanting to add a factory nav unit to my 2003 expedition, and have found one at a local salvage yard in a 2004 expedition for $150, but dont want to wast my money if if wont work in mine. I have had many other vehicles in the past and always added factory navigation, but cant really find out much about the expeditions. I have even read in a few places that they actually wire the vehicle different if you have it from the factory... Is this right? I thought they always wired vehicles the same and installed all the options twards the end. Thanks


