I have an older wired system and mine just shows a white line across the monitor .......some of the time. It fails more often that it works.
I suspect a bad connection at or inside the camera, since when a guy started moving it around it worked.....for a few minutes.
While there likely is a power tap somewhere inside, the actual connections to the camera should be at the back of the camera or inside the case.
'07 Damon Outlaw 3611
CanAm Spyder in the "trunk"