[Vrobert]

At the risk of plagiarizing the CubCadetMan I will post his drawing that I found very helpful. Here is my understanding of the regulator, but I could be wrong. Feedback welcome. Flame on! I can take it!

The two relays in the regulator serve three functions; one to regulate the generator output voltage, and the other to disconnect the battery from the generator if the generator isn't outputting voltage or if the charge current into the battery is too high.

The leftmost field relay is normally closed, shorting the generator field terminal to ground. When running, this contact is quickly cycling on and off to maintain a proper charge voltage (around 14 volts). The generator charging output can be tested by grounding the field wire momentarily to verify the output voltage jumps to max, about 16 volts.

The rightmost relay has two controlling coils. The lower thin wire coil connects the battery to the generator only when it is outputting charge voltage to prevent draining the battery when parked. The upper heavy wire coil disconnects the battery from the generator if the charge current into the battery is excessive.