I've seen this question asked a hundred times and seen almost as many different answers. Does anyone know it the wiring connections are different for a single disc stock 2004 F-150 stereo as opposed to the 6-disc changer unit. As I understood it, the single unit requires one wiring harness, and the changer requires two. I've seen several posts where people have bought a 6-disc and said the radio worked fine but not the CD-changer. I can't see all of them getting just the changer damaged in shipping, so I assume it has something to do with the wiring harness. I'm still trying to sell my 6-disc changer and I don't want to sell it to someone who won't be able to get it hooked up correctly and will be unhappy.

 

I just removed my 6-disc in dash unit, it definatly had 2 wire harnesses to it. When I reconnected my aftermarket unit, only 1 was used to hook it up. I have no idea what the second harness is for, but it is there.