What the Hell is That?
So I was out this weekend. Boat idles fine, Tach is correct as least I think. The problem is under load it will be at say 3500 then drop to zero then shoot back up. at even higher RPM it will stay at 0 until I let up off it. I don't think its a short problem cause most of the gauges are piggyed back together and the Amp meter doesn't show an Excessive load (been there done that with a shorted water temp gauge) I believe its either the Coil (Mallory Promaster) or the Ballist resistors going bad. Tach is a brand new SW tach.