tach on the raider has 3 wires. 2 are black, tied together, and are grounded. the 3rd is yellow, and is spliced into yellow wire that goes from the engine to the rectifier. i presume this could be right but have my feelings of it being wrong. is this the right place for this wire, if not where does it need to go? tach just slightly flinches every now and then, its not a RPM dependant relation to the tach flinch.