[birdleg]

To me it sounds like a battery is shorted and reading double voltage. I have had several 12 volt batteries in my precedent fleet that when off the charger batteries read fine but soon as the charger kicks on a battery is reading double voltage throwing the ammeter all crazy and dropping to zero. This may or may not be it but I'd check voltage while on charger. My carts would read 49 volts ish off charger then soon as it kicks on jump straight up to 59 volts or so. Because one battery is reading double voltage and is shorted. It's at least a thought anyway