[BulletOwner1]

Not sure why the cigarette lighter connection is in question but maybe the actual plug in is not making contact well. If you want to tap into a 12V source under the dash you could just tap off the wire that runs to the lighter. That way you wouldn't have to figure out which one of the thousand or so other wires under there would be a good source. I'm sure you know this but make sure it's fused. The lighter's capacity is much greater than what the monitors.