started out this morning 2008 F150 5.4L started just fine as it did yesterday in 13* weather, drove about 12 miles the battery light comes on, finish my trip, around 25 miles each way mostly highway, without turning the truck off and on the way back the electrical gauge starts to lean to the left, the wipers are slowing down and the whole dashboard is dimming..... I'm starting to think the alternator is failing so I head right for the stealership hoping to make it. Another 5 miles on the Interstate and no wipers, lights, dashboard lights, defroster or radio, complete blackness and it starts to miss a bit and I barely make it off I 276 and off to the side. Never a days trouble in the 8+ years I've had it. The temp gauge never moved and no I didn't raise the hood to investigate with the miserable weather and the traffic. Again the truck started fine yesterday in 13* Wx.....could an alternator go that fast ? Truck has 57K on it, got transferred(FD) close to home around the time I bought it so that's the reason for the low miles. Waiting for the call from the dealership
thanks

 

8 years old? Not unusual for an alternator to die.

 

Ok glc, hoping it's only that, really like the truck.....first time on a flatbed since I took delivery in late 2007
thanks

 

Dealership just called and said they can't find anything ?? said they'd let it run for a while to check further ? Any experts out there that could advise?, should I just get the alternator replaced? any questions just fire away..... frustrating
thanks

 

Just got the truck back, they replaced the alternator and battery.....I'll let you know how it makes out.

 

Did they both test bad or are they just shotgunning parts at it?

 

battery was about 5 yrs old and they couldn't get it to charge after I broke down and the alternator was bad , it's been about 3 days and the truck is running fine
hope all that stuff is behind me
I even changed the oil fearing some fuel may have leaked down while I was huffin', puffin' and buckin' along trying to get off the Interstate , but I smelled the old oil and it didn't smell "gassy"
so I guess I'm good to go
Oh yeah, I insisted on a Ford alternator.....it wasn't cheap :-(
thanks all for the info here