I got a pair of headreast DVD/Monitors for my wifes 05 X5. I wired them the the rear aux jack ( cig lighter jack ) which seems to be a constant 12v source. It worked fine the first day, but now I'm having problems with them powering on . I'm not sure if its because when the truck goes into sleep mode or what . I was hoping that would work so my kids can turn it on without the truck being turned on . So , anyway, I was hoping somebody knows where theres a switched 12v power wire under the dash that I can use to power these up. The units have a 30amp inline fuse on the red power wire. Thanks in advance ,