[djmoore85]

Sounds almost like you have a short somewhere. Wierd noises and then a low-pitched noise after vehicle is off would seem to me to point to a short. Now is the low-pitched noise coming from the speakers or the radio? If it's from the speakers after vehicle is shut off, then you have short somewhere on the speaker line or a ground-out where something is completing a circuit, so to say, causing the speakers to go off after power is cut from them by the radio. If all this is coming from the radio, it's either a short or a bad unit.