Re: Bought a 1985 Case Ingersoll 446
I have seen wiring, and I am not joking, where they wanted to make the wire longer and they used 2 splices to add a section of wire.
Most electrical problems on these tractors start at the ignition switch. The battery wire going the switch is full amperage and that often gets hot, then it gets a bad connection which just gets worse over time. The PTO micro switch goes bad and I think the 2 safety switch as in series. Sometimes the micro-switch just needs the metal tab rebent to activate the switch when it should.
Both the owners manual and the parts manual have the wiring diagram. But, it is usually the owners manual that has the wire colors listed. I believe this site has the manuals and parts dealers. Otherwise, a Google search will work. You just need the version manual for your version tractor.