Hello all, so as some of you may know/remember, I drive a 99' Ram 2500 with the 5.9l cummins. I've noticed something "interesting" within the past few days. I'll be driving along at 60mph and I'll look over and see the voltmeter is at 12ish volts. This happened once the other day, and went away after 2 minutes or so and then again today. Today I was making a U-turn and noticed it, accelerated and it stayed there, pulled off after a minute, shut off the engine, started it, and after a few seconds it went to 14 volts. Changing RPM doesn't appear to change anything when this is occurring, but the reaction time on the stock volt meter is slow so the rpm could be making it increase slightly. I have verified this voltage as I have a ham radio installed that tells me the voltage when I first turn it on. The first time this happened I thought the alternator had just died on me, but since it still appears to charge after these events occur, I can't imagine the alternator is to blame as once they die out their usually not going to come back(although I'd prefer this since replacing an alternator would be pretty easy). The only thing I can see causing a large drain on the alternator is the grid heater coming on, but since this has occurred at 60mph, the heater should DEFINITELY not be on at that speed, since it is supposed to shut off when you are over 20mph. Also, I'd expect a noticeable power difference if the heater was on at that speed, but it has run just like normal during these occurrences. Could this be the voltage regulator going out? Or somehow the grid heater? I'll be sure to double check, but I'm pretty sure it isn't any wiring shorting out.