I have a 4-stroke 40hp Yamaha (2001 model). It is a F40TRZ. I bought a trim gauge (6Y5-83670-11-00) w/wire harness that is supposed to work for it, but I can't figure out the the wiring. It has a square harness that should fit to the engine, but there are several wires coming off the trim gauge in addition to the square fitting. I think the blue is for a light, the black for ground? but where do I need to hook up the others - a black w/purple and yellow w/purple? Any help is appreciated.