First off, is the amp gauge on a '71 an 'ammeter' and therefore measures amps, and nowadays gauges voltmeters? The reason I ask is because my gauge goes to -40, 0, and 40, while it seems nowadays just has 0, 6, 9, and 12. So are they measuring not only different units but different types of charging? What is nominal on the stock gauge for a '71?

Also, kind of silly to ask the aforementioned since my gauge doesn't work. It rocks around in it's little case thing and then power was put to it. It was new and the guy who sold it to me said if it was loose and touching the case and got power to it it would have been grounded out and therefore burnt out. Does that make sense to anyone?

Thanks..

If the terminals on the back of the amp gauge grounded out on something it would cause a direct short and might fry the gauge.