[verbal719]

I have a 99 mustang 3.8 and I just bought a Pioneer car stereo. I had another after market deck in that worked fine. I took it out and tried to install an Alpine I got from a friend. I hooked up all the wires as normal and the stereo did not turn on. I figured the stereo might have been broken. So I go today and buy a brand new Pioneer. I hook everything up as normal and still the power does ont come on. There is power going through the red power wire, but no power going through the yellow wire. I checked all my fuses and none were blown. Im very frustrated and need some help. I dont know if maybe there is some kind of security thing that is making it not work or if it has a bad ground???????? If someone could help me it would be awesome.