Reversing camera installation

Since you don't have your year/model listed it is hard to give the best answer. Will you have the camera in the tailgate handle or elsewhere? I have gone from the HU behind the driving pedals, down the left side under the door floor panels and through a hole behind the rear seat in the rear left corner. The rear and left side bed panels will have to be removed and the wires run along behind the left inside bed wall. It is time consuming but better than going under the bed as the wires are protected. The is also a wireless option available if you search the forum.

See post 13 here...
http://www.ridgelineownersclub.com/...233-kenwood-excelon-dnx893s-hu-install-2.html

See posts 12 + 13 here...
http://www.ridgelineownersclub.com/...ronics/44250-kenwood-dnx9990hd-install-2.html

.

Here's the Honda route which terminates under the driver seat. Once to the front seat you can meander your way over or under as you choose to get to your final location.

https://www.handa-accessories.com/ridgeline/backupcamera.pdf