daytooday

Changed out a blown motor, 2002 Mustang 3.8 for another 3.8. It want start, the starter relay is new. I jumped a wire in the fuse box at the starter really. The motor turned over. When I turn the switch on at the starter nothing happens inside, no dash power at all, doesn't try to start. I think this is saying the problem is between the starter switch and the fuse box. But what is it? PLEASE, forgive my ignorance I am a noob