Originally Posted by Captain Bill
Where are you measuring the output at the alternator or the battery. I would suspect a bad wire either the field connection is not getting any voltage or the output wire is bad, if you are measuring at the battery.
Another possibility is if you have a switch between the alternator and the battery perhaps it has gone bad.
With the field voltage set at 12.8V from Start Bat, I measured Alt+ to Alt-, Bat+ to Bat-, Alt+ to Bat- and Bat+ to Alt- All we 12V. No measurable voltage drop across the Alternator shunt. If I put an isolating diode between the alternator and the battery bank the measurements are Alt+ to Alt- and Alt+to Bat- 12.6V,
Bat+ to Bat- and Bat+ to Alt- were 12V. Voltage drop measured across the diode as .6 volts. So voltage at the alternator, but no current