[folivier]

I ran the cable in the overhead panels on the passenger side over the valence. Used a fish tape but had to unscrew the panel at the very front, then in a couple kitchen cabinets, open the switch panel over microwave, unscrew the panel over the bedroom window, then the panels in the closet. Then I ran the cable behind the tv in front and drilled a 1/2" or so hole next to where I mounted the monitor under the tv cabinet. I was able to grab 12 volts from the tv antenna power booster (not using the booster). I think the one I have uses an s-video type connector.
Did you buy the monitor with camera and multiplexer? You can email or call them and they might have the adapter you need for your old cable.