Car Stereos: Pioneer Head Unit will not turn on, pioneer head unit, chevrolet 2500

Question
I have a 2005 Chevrolet 2500. I am trying to put my Pioneer Head Unit in it is a DEH-P2900MP. We have checked the wires and there is power but the head unit will not turn on. We even checked with another head unit and nothing. It like the head units just arent getting power but our power detector says we are. If you could please help.

Answer
Michael,  Does your power detector test the red and yellow wires.  They must both have power, before the head units will work.  If they both have power, then you must check and make sure the ground wire is properly attached to a good grounding point and secure.  If those two steps are done, the head unit should power up.  Even if there is no sound, it should at least light up.  If it is not lighting up after those checks, then there is something wrong with the unit.  Hope this helps, Scott