my old headunit is not turning on at all now. I pulled it out yesterday to rerun the power wire, got it rerun, and now it won't turn on for anything. I have tested the power wire, its getting power, and im pretty sure on the harness the black wire is the ground, cut it and ground it out, and it grounds out right...tested it wiht the multimeter too...but it will not come on for anything...it came on for maybe 2 mins earlier, i move it and was baout to put it back in the dash and it cut off again...what the hell else should i check??? i want to get this thing put back together.