Trailer Wiring For Touareg How Do I Add Amber Side Running Lights To A Four Pole Flat Boat Trailer Wiring System?

How do I add amber side running lights to a four pole flat boat trailer wiring system? - trailer wiring for touareg

I would add yellow lights next to my boat trailer, which has four pole flat ribbon cable. The yellow lights have only one hot wire and "automatically" stick connected to the frame. Give not only the power in light brown with a live wire running a light amber? It seems to me a complete circuit, but only connect a cable with the lightbulb, so I have no other way for you to see it. Thank you!