Since we can't see your wiring, I can only guess. But the voltage at the battery or on your voltmeter should read from 13 to 14 1/2 volts with the car running. I had a voltmeter in my dash which I like as I could just glance at it and see if the alternator was charging the battery.
As Joe asked, has it ever worked properly, and if so did you make any changes at all before this started?
Ron
