The oil indicator light and the tachometer on a Honda 1990 BF50A has stopped working. The engine runs and starts fine. When the control harness is hooked up to a different engine the oil light and the tach work. When the engine is hooked up to a different control harness the light and tach work. One mechanic replaced the regulator rectifier assy (31600-zv5-003), the ignition control module (30580-zv5-003), and the pulser coil assy (30400-zv5-003). The oil light and tach still don't work. I started checking for a bad ground and the only other thing I could find was the lead wire (40219-zv5-003) going from the swivel bracket to the case extention had gotten hot enough to melt the insulation off the wire. All the other grounds seemed fine. Any ideas?
