Folks here who have skills in electronics (I know there are many of you ), I have an aftermarket backup camera with 3 wires, RED (power), BLACK (ground) and YELLOW (video). The red and black are regular wires and the yellow is an RCA connector. Most of the cheap aftermarket cameras come this way, easy enough. So looking at the wire diagram coming out of my OEM navigation I have 4 wires that need to hook up to the backup camera. I have Power, Ground, Video +, and Video -. I'm scratching my head here ? What is video (+) and video (-)? Do I need to modify the yellow RCA video connector from the aftermarket camera to get it all connected properly? Thanks for any help you can offer.