I hooked up the alternator without the tach drive and with all the lights on, including the driving lights, it takes about 1200 RPMs to keep the ammeter needle in the center, (Neutral), anything above 1200 RPMs is charging. About 2000 RPMs the unit is charging about 10 amps. Now that's on a battery that's near fully charged Optima battery, after a few minutes the needle went to almost zero. I do have to re-wire the dash light, as it is staying on while running. A positive ground system causes extra work in the wiring due to the relay needed. I would have converted to a negative system if it wasn't for a fairly new electronic SU fuel pump. If Dave was still with us, I would have had him convert it to negative. Moss order not here yet. PJ