The ammeter is a shunt, a resistor. To read correctly, it passes all current. As a resistor, it has been the source of fires over the years. Increasing the alternator output increases that risk, and a fire extinguisher should never be Plan A. I changed the alternator to an 85-110A, not a one-wire, coupled the under-dash leads, ran a 10ga and fusible link directly to the battery under the hood, and changed the ammeter to the upside down Sun voltmeter trick. I also swapped to a Transpo adjustable regulator and set the voltage at about 13.4V. The voltmeter sits there like a rock, a/c, lights and all. Appearance wise, the gauge blends in well in the Rallye cluster, the alternator looks stock, the regulator is a good match, and the 10ga wire you have to look for.