You can't do this like you suggest if your trailer is not wired correctly or doesn't have these "Marine style boat trailer lights" of which you speak (which I am not familiar with). A 4 wire trailer will not work on a 5 wire Goldwing just by running a parallel plug and a 5 wire trailer will not work on a 4 wire vehicle either. That is exactly why I installed the lights I did on my Aspen Classic and wired them to accept either 4 or 5 wire input but a jumper wire has to be installed for 5 wire operation. As you can see from the diagram, on a 4 wire trailer the left and right brake lights are separate and also carry the left and right turn signal (a flashing red). On a 5 wire trailer there are extra lights (usually amber) that carry the segregated turn signal and the red brake lights are tied together. Now, if these Marine lights can sense either condition then I guess they must work as you suggest.
New 4 and 5 Wire Configuration e.jpg 201.7KB 0 downloads