Cub charging

So here's the question: How can I troubleshoot the generator and voltage regulator? And how exactly does the voltage regulator work with the generator?

This tractor was converted from magneto to distributor ignition some years ago. Plus, my wiring diagram shows the voltage regulator having 4 terminals. Well, mine has 3 terminals so I didn't even touch that wiring. If it worked before it should work again.

Thanks for any help, Chris

There is one relay that simply opens when the generator is not putting out enough voltage to do anything. This prevents the battery from discharging back into the generator (which would actually turn the generator into a motor).

There is another relay that monitors the output voltage, and maintains the generator at fairly constant average voltage. It does this by opening and closing rapidly. The higher the percentage of closed vs open, the higher the output voltage of the generator. The contacts of this voltage regulator relay short the low side of the field winding in the generator to ground, causing current to flow in the field winding, causing the field winding to make a magnetic field, causing the generator output voltage to go up.

The last relay is the current regulator, which opens the field winding when the generator tries to put out too much current, so you do not burn anything up.