OKay, please help me save whatever hair i have left because i have pulled the rest!!!!!! Last week, I sold my DVD head unit . Un installed it and let it go. Now, went to go install an old head unit i had but im running into a problem. After connecting the harness together, I have no power getting to the unit. Checked wires, nothing. Tried a different head unit, no power. I have tested to see if power is in the wire and it is. All wires are connected correctly, no fuses are blown, and ground is good. What could it be? Could i just by chance have two faulty decks? Now , the install is minus the part you need to keep onstar. I have run power from a keyed fuse under the hood to the unit. Could the harness be messed? I just cant get over how everything was good then deinstalled and now its no good. Does anyone have any insight to what my problem could be? MUCH APPRECIATED GUYS!!!!!