Originally Posted by khern11

You probably figured it out by now but if you havnt...

the RED3 and RED4 in your diagram is an independent wire that just runs along the yellow AV cable. I used it to tap into the reverse wire of my head unit and I wired the other end to the red power wire of the camera. This worked for me.

Basically the wire is there if you don't want to tap into the tail light reverse wire to power your camera and you rather get it from the front of the car.