PerfectPoise
+1y
the yellow wire is constant power, thats the fuse you might have blown. Check that one, no matter if the ignition is on or off the yellow wire is hot. Unless of course you blow the fuse. The red wire is the ignition wire and only gets hot when the ignition is on or in accessory. There are fuses in your dash and possibly under the hood. Check your manual to find out, if not check the fuse on the back of the cd player. Start there....if nothing then bring it to a professional. I see this all the time when people who arent audio installers try to "do it yourself" and cant figure it out. good luck