A stator to negative connection is used. Some alternators provide an "N" or "R" terminal for this.
With a 3-amp axial diode in-line this new connection can power a 5-wire relay like a Bosch type. You will need to connect the wire to any stator terminal on the alternator.
Then it runs to and through the relay coil.
Exits the other relay coil terminal and then connects to chassis negative.
Run an new wire to the ignition switch circuit. Connect it to an outboard relay terminal. There are 3 remaining relay terminals. Choose one of the two most OUTBOARD of the terminals.
The center-most relay terminal connects to a wire then to a two wire pilot light bulb or audible alarm. one wire left to connect. Connect the other bulb or alarm wire to chassis negative.
No stator voltage means it will not pull the relay contacts open and open the light or alarm circuit. Being powered by ignition the light comes on when the key is switched on verifying the circuit is viable.
I you use Ignition Switch terminal A, the circuit will operate only with ignition switch turned on. The accessory position will not activate the circuit.
A muted pleasant chime is the hot setup for me. Vehicle gauges are less than worthless. I note that I tend to see them when steam boils out from under the hood, a knocking sound is out of rhythm with Ziggy Marley, or the lights go dim.
