The machine has 2 AGM batteries installed. Battery connections are clean on both batteries. When manually charged they hold and keep 13.1 volts, they are 4-5 years old but are regularly maintained and in heated storage. This unit can run for the better part of an hour NOT charging before starting is slowed. Take this as note: the testing I have done for the stator is while running and unplugged, never back probed and tested at the engine bay and at the voltage regulator with the same results. The battery voltage is taken at the regulator plug while running- the plug disconnected voltage and battery voltage are the same, suggests no voltage drop on the wiring. That said I have not tried that circuit with a load like a headlight or two. There are multiple extra ground circuits now, if there was a wiring issue I don't believe it to be on the ground side. When working the regulator, engine running is putting out charging voltage, 12.8-15.1V. The rhino dash has a battery gauge and I have installed and aftermarket Chinese Voltage gauge/USB point. The rhino battery gauge reads 0.4-0.6 volts lower than actual battery. I believe this is to be expected as the battery gauge runs through the Ignition switched relay. Anything else on this circuit could cause that drop including the relay. I can watch the dash and the aftermarket gauge read from charging voltage 13.1-15.1v then suddenly stop when the machine returns to idle and read 12.8, 12.6, 12.4, 12.2 as you continue driving. Again it will not start charging again until you turn the machine off and restart. It will continue to charge for ever until you return to idle. For example, I close the gate behind me, start the machine and run from one end of the section to the other, it will charge the whole time running down the field until i get to the next gate and returned to idle. It won't charge again unless I shut off and restart. The Challenge is that the circuit is so simple. 5 wires, 3 from the stator -A/C voltage, one Battery positive, and one battery negative. There is also one factory ground wire to the Regulator body bolted to ground and I have added an additional ground to that same point to the secondary Battery ground. Also note that the RM Regulator has a thermal switch, to shut down and let it cool if it gets hot. At this time I am running no loads. The factory Regulator does not have a thermal switch but gives the same results.
Thanks for giving this a go, I'm sure I have overlooked something obvious.