by 3 prong i'm taking it that there are also on 3 major wires coming from the back of the alternator..the 1 wire is hot all the time, but there should also be a charge back wire the feeds directly to the negative battery terminal...the other wire could possibly have many other wires connected 2 it which are used for such things as the starter, radio, and any other component that requires a
12-14.7 volt feed..the power for your warning lights can be fed by the battery itself because if you turn the key on/engine off they should light up- posted
20 years ago