Was just driving on the highway at 75mph with the cruise on. Outside temp is about 12°F. Had the heater blasting on defrost. My cruise shut off and then I noticed that my headlights were flickering. Looked at my charge guage and it was above 14. A few seconds later the charger guage went down to normal and I set my cruise again. A few miles down the road, the same thing happened again. Now I'm sitting at work and it's charging at around 15-16v. Shut the truck off and turn the key back on (not starting) and the voltage is at 12. Started back up and still charging high. Anyone have any ideas?