Strangely this "fully loaded" rig didn't have a backup camera. So I just rectified that today. Used a generic eBay camera with wireless RF transmitter because I was lazy and didn't want to route wire the entire cab length. Very happy with the decision. A little interference occasionally, but great picture otherwise.
For headunit, used the olive green wire in the drivers A-pillar to trigger the headunit reverse trigger so it switches to camera automatically on backup.
For the camera, it is powered off the reverse + wire for the passenger backup light. Routed the wire up through the rear hatch rubber pass-thru...that was a major PITA...wow! But totally worth it so the install shows no wires.
I have the bottom right setup
For headunit, used the olive green wire in the drivers A-pillar to trigger the headunit reverse trigger so it switches to camera automatically on backup.
For the camera, it is powered off the reverse + wire for the passenger backup light. Routed the wire up through the rear hatch rubber pass-thru...that was a major PITA...wow! But totally worth it so the install shows no wires.
I have the bottom right setup