I just installed a new 1 wire alternator with one of those mini regulator on the back. I have underdrive pulleys. My guage is reading only 10 Volts. Can I get my alternator to excite before 2000 RPM?
yeah, you will need to spin the alternator a little faster. I don't recommend an underdrive pulley for an alternator on a street driven car that must idle for extended periods of time.
10V is extremely low. Charging voltage, even at idle, should never be below 13.5V when the field is excited (assuming the regulator is doing it's job).