I have a 2008 mustang with the basic 4 speaker system. I am putting my Pioneer head unit in it that I pulled from my 2005 focus and they use the same wiring harness. When I get it all plugged in the radio doesn't power on so I get ahold of crutchfield. They tell me that I have to run a wire from my fuse box. Does anyone know which fuse will allow me to run 12V when the key is on turned "on" or "accessory?" The way I have it setup now is that it is on a constant 12V, Also if anyone knows where a good spot to run a amp power wire through the floor panel into the engine compartment that would be helpful

 

Yup crutchfeild is right no switch power at the radio they started that later 2008 models. Sucks, but chevy drivers been dealing with this since 2000.

 

Right but I was wondering if anyone knew if there was a fuse in the fuse box that turned on when the key was turned on, i'm using a constant right now and my radio is on all the time.

 

nope, but quick and easy way is to bust out the handy-dandy voltmeter (if you dont have one, GET ONE!)