My question is I'm trying to troubleshoot my sony xplode head unit and should I be able to measure resistance on the 12v ignition to the ground? I get 13 something v when I do constant to ground but nothing when I do 12v ignition to ground. The reason I ask this is because the cd player wont turn on, it will display the clock but when you hit play it shuts off. Which tells me its not getting any juice except for constant. Is there anything I can do about it or is that cd player just toast? I just bought it and it was supposedly never used.