Yeah a flakey alternator probably or lord help you a loose connection somewhere. Alternators will start to get intermittant when the brushes or regulator are on their way out. A low voltage output will cause the light to flicker. An output that is jumping around will also cause the light to flicker.

What do you mean the alternator looks full?? Did you measure voltage at the battery? Was it something like 14volts to maybe 18? What is full?

Good Luck,

Jim Henderson