My boat needed a new starter and solenoid. The old starter had a 3 wire solenoid, the new solenoid has 2 wire connector. If I hook up the battery cable, the charging wire, and the bigger of the two wires left the boat will run flawlessly and all gauges work. My question is what do I do with the remaining wire. The wire appears to run to, well at least I'm guessing, the oil pressure sending unit at the back of the engine. The oil pressure guage still functions with out any problems though.