Mike,
It's a 1996 tandem Axel Tennessee Trailer. It came with the boat when I bought it 3 seasons ago but this is the 1st year I have trailered it. There is a "key/pin" thing (lol, I know, not sure on the terminology) that is attached to a wire about 1 foot in length. I'm really not sure where it goes but it sounds like it may be what you are talking about. I am going outside right now and look at it again. When the brakes engage there is a big bolt on the toungue that slides in the up position. When backing up any hill this always happens, but only when the boat is on the trailer. I'll check it our right now..
Thanks again Mike,
Terry
Terry Sloan and Diane Alley
1997 210CCR
Chattanooga, Tn.