[NJARC] Ampmeter on 1935 Harley Davidson

[Sal Brisindi]

My 1975 Pontiac Trans-Am has a voltmeter and to me it was a good indication of the charging system. With the car running and the meter reading 12 volts or less, your alternator is not doing its job and going on the fritz...  If the meter read 13 volts or more especially with the headlights on, you were golden!

Now my 58 Impala has an idiot light but it is disconnected since it has a 1 wire alternator so I was thinking building a simple circuit with a LM339 Comparator and adjust the set point if the voltage drops below 12.2 volts, or somewhere around there to be determined by experiment, the idiot light would come on... 

Sal