Could I see the same change at the ammeter?
I know it was constantly discharging when it was running, and it really went down FAST whenever I turned the headlights on.
Yes, if the ammeter is discharging, (reading below zero), then you are running off the battery...
You should have 12.6 Volts on a good battery with the engine off...
With the engine on, you should have between 13.3 - 15.0 volts...
If your ammeter is reading below 0, then you are discharging and running off the battery charge... It will run until the battery is dead, then you may jump it, but it will only run for a little bit, then die because the battery is not fully charged....
