That tells me there’s no weird power draw from the light/brake systems, which is good!At idle voltage is 13.1 volts no load
At 2k rpm 13.4 volts no load
At idle voltage is 13.1 volts with headlights on high beam
At 2k rpm voltage is 13.3 volts with headlights on high beam
At idle voltage is 13.1 volts with headlights on high beam and brake pedal depressed
At 2k rpm voltage is 13.3 volts with headlights on high beam and brake pedal depressed.
But, I would expect you to be in the 14’s voltage when running. I really don’t think your alternator is working properly.