Has anybody seen this before?

My Battery Light comes on at about 70 to 75 mph and won’t shut off till I come to a complete stop or slow down to about 30 mph.

The Battery Gauge sits where it always sits, the truck starts fine

The truck is a 2003 with about 112k on it, I think the belt maybe slipping

 

Got it


turned out to be th alternator

 

Had the same on my 02 4.6 turn out to be the voltage regulator in the alt