Boat Trailer Wiring Diagram: Understanding 4-Pin Connections

Question
i am changing a boat trailer to a flat deck and have no idea on wiring diagrams.  My 4 prong has white, 2brown out of the one prong, yellow and green.  Can you help me?

Answer
Hello Mike,
The wires are for turn signal and marker lights(parking). Some trailers will have lights on the sides that are lit when the light switch is on to parking lights or headlights on. The wires are used for the following(I'm not at my shop so I can't be totally sure without looking at the book but you can use a 12 volt source to verifiy the wire colors)
white=ground---yellow=left turn signal/stop---green=right turn signal/stop---2browns are for marker/park lights. If you need Tech Help in the future please feel free to contact me direct at: tdeser@zoominternet.net

TOM,
T&D ELECTRONICS