mike-s wrote:
Is this when watching a TV channel, or do you have another video device like a DVD player sourcing the video, and how is it connected?
"Wavy lines" are not a symptom associated with a digital video issue. My guess is either you're using an analog connection (RCA jack - composite video), or the 12V power isn't steady and is effecting the backlight of the TV. If you're using composite video, change to an HDMI connection if possible.
All I have is the RCA jacks coming from the Radio/DVD player (factory install) so HDMI is out of the question. I still think it is the power source.