Battery Light Flashing!

[Chris0214]

I have a little trouble so I will throw this out to all you guys who know way may about this than I. I have a 1999 F350 with the 7.3 diesel engine. The battery indicator light comes on stays on sometimes and flashes on and off other times. The alternator was replaced 8 months ago and it is still outputting like it should. I did have to replace both batteries recently though. Any ideas what may be causing this?

[SCUFFY828]

alternator 99 out of 100 times, if not bad connection at alternator,ive seen alternators do wierd things even if showing to be charging