Do you have 12 volts on the brown wire with it disconnected from the alternator and the key in the on position?
If you do the voltage comes from the volts socket.
You can ground the brown wire key on and the volts light should come on. Use a 2-5 amp. fused jumper for the ground wire. Not a direct short.
Finally use the test hole in the alternator with a small screwdriver and ground the side of the screwdriver to the case and push it in until it hits the contact area. This is with the connector put back into the alternator. If it lights replace the regulator inside the alternator. If it doesn't light it;s the alternator, brushes, slip ring or windings.
If you do the voltage comes from the volts socket.
You can ground the brown wire key on and the volts light should come on. Use a 2-5 amp. fused jumper for the ground wire. Not a direct short.
Finally use the test hole in the alternator with a small screwdriver and ground the side of the screwdriver to the case and push it in until it hits the contact area. This is with the connector put back into the alternator. If it lights replace the regulator inside the alternator. If it doesn't light it;s the alternator, brushes, slip ring or windings.