1995 Yamaha 250 Saltwater on a Sailfish 236. Yamaha digital multifunction tach and speed gauges. When I turn on the ignition key the gauges remain dead but when I start the engine the tach gauge shows 0 mph and nothing else and the speedo still remains dead. I can slightly bump the ignition switch and the alarm will sound but stops when the ignition switch is turned all the way to start. I have checked all connections and can't find any that are loose or corroded. Could this be a bad/faulty ignition switch?? I hate to buy a new one since they are $147 if this is not the problem. Is there a way to test the switch and the gauges. I have a digital multi-meter but need to know what and where to check the circuts.