Yes you did post this on the wrong website. This forum is dedicated to those hobbiest that wish to integrate a PC into their vehicle and in some cases we do not uses standard aftermarket equiptment to do so. If you wish to learn more about the subject, welcome to mp3car.com. Otherwise you may get a better and more timely answer by visiting a site dedicated to general car audio.
If I were to guess what your problem, I would have to say something is wrong with either your wiring or your newly installed HU.