This seems to be a touchy subject for a lot of people. The original mopar ammeter setup was a bad idea. The entire current load of the car went through a 1/4 inch spade terminal into the gauge and back out through another spade lug. this is more current than these things are rated for. In about 1977, Mopar went with an external shunt for the ammeter and less than 1 amp flows on the wires that used to carry the entire load.
Unfortunately it takes a good bit of rewiring to bypass these connectors and usually gets expensive if you have to pay someone to do it.
My opinion (and Autometers) is to go with a voltmeter. The only vehicle that still comes with an ammeter is a riding lawnmower.
