I have a '92 85hp yamaha and I'm tring to add a yamaha temp gauge. It has 3 wires off the back along with the 2 lighting wires, yellow,light blue, and black. The light blue one is giving me the trouble. Where does it connect to? The guy at the yamaha counter said it ties into the overheat alarm sending unit, but how. My 2nd problem is that I got a yamaha dig speedo and the "set/mode" buttons do nothing. It has a 's video' type connector on the back that is not hooked up. Should it be? Where can I locate a schematic on this? I do appreciate all the help I've recieved in the past very much. Everyone here has saved me a lot of time and money that the wife doesn't like to share with a mechanic. Thanx again