My one-wire alternator has worked flawlessly for 8 years on a 12 volt conversion of an Advance-Design truck (1954 - a truck with a temp gauge and an ammeter). No special wiring is needed. The alternator kicks in at about 900 rpm and then works at all rpms, including 500 rpm idle. Since I reach 1000 rpm when I first start my truck, I have no charging problems. No boob light on A-D trucks, so no boob-light-wire needed.
If my truck did not have gauges, I would get a 3-wire alternator - no question about it, for me.
