I'd like to add an alarm
light to my control panel
so that if the alternator
(e.g. if the fan belt belt breaks), the light will come on.
I've seen the circuit before somewhere, but can't remember it. I think, you have to apply +12v from the battery
to one side of the light, and the positive output from the alternator
to the other side, so they cancel out when everything is fine, but the light goes on when the 12v is not coming from the alternator, or something like that.
Can any electrical
wizard help me out please ?