I had EXACT.Y the same issue, solved EXACTLY the same way.Finally got a chance to look at everything on my trailer, it ended up being the wire inside the axle that goes from one side to the other. It was worn bare about 2 inches long. I took the wire out of the axle and secured it on the outside of the axle tube. Brakes work fine with no message on the dash. I'm glad it was an easy fix because me and electrical don't get along.
Kevin