Yes, with the current configuration, the alternator will only show an output of 13 volts max at full throttle. When the tractor is at idle, the meter shows a constant 12 volts. I noticed, when i touch the meter to the pin on the left or the silver guard at the bottom of the alternator, it shows a constant 13 volts and at full throttle 14 volts. I was told that this JD has a regulator that only allows the battery to charge when needed. I just got the tractor back from the shop from the alternator being repaired.