[bestgenman]

Kyle, the two sensors for protection are ground (negative) sensing.  Don’t confuse them with the sensors for the gauges.  The shutdown switches have bullet style connectors as opposed to threaded studs and nuts. If you lift the wire from the sensor and it still shuts down, then they are not your problem.  As mentioned by other esteemed contributors, check your fan motor while starting.  If it is turning then your have some output, if not it could be the excitation system (voltage regulator) or brushes.  I don’t see any reference to the engine hours but it takes thousands to wear out brushes, that doesn’t mean they aren’t suspect but I’d rather think it’s something else.
You are welcome to call me but leave a VM as my phone won’t ring if you aren’t in my contact list. 614-271-7488.

I’m not sure of the switch style on your Perkins. It won’t hurt if you disconnect switch and sender. If you hold the solenoid in to keep it running, check your fan.