I've got a 2008 F150, 5.4 that a couple of weeks ago while driving the lights went dim, radio shut off and fan slowed down then the front hubs tried locking. It did the twice over a 30 sec time span and lasted for about 5 sec each time. I took it to the dealer (very trusted) and they tested the alt and battery and couldn't find anything wrong. Fast forward to last night I noticed that at an idle the headlights where flickering. I tested voltage at the battery with engine a an idle and the voltage varied between 13.8 to 14.8 and changed so fast that it made it hard to get those numbers. What's going on with this thing? Is it possible that the voltage regulator is going bad and is it internal to the alternator on these?