1995 FLD120 with a C15 started overcharging on me last week. At idle would be about 14.5 volts, but anywhere from 15-18 going down the highway at 1600 rpms. Put my spare alternator on yesterday and it's doing the same thing, but not quite as bad. Have 2 groups of 2 batteries that are about 3 years old. Unhooked each group individually thinking may have a bad battery. No change. Was -10 here over the weekend, and 20 yesterday. Started up on its own. Not sure what to check next. Spare…
Overcharging FLD120
