Driving down a pretty bumpy road tonight my battery light started flickering just a bit. It continued to flicker very dimly even after I was past the bumpy road. I've got a voltage gauge, and even when the battery light was flickering it read a steady voltage. I've also got a lot of additional lighting on the car, and even with the fan on high and about 350 watts of lighting energized the battery light still only occasionally dimly flickered. So:

1) Is the bumpy road a red herring, am I due for a new alternator?

2) If I do have a faulty alternator should I expect to see some indication of it on my voltage gauge?

3) Is there some obvious possible other point of failure or loose contact that I should be examining, that might trigger the warning light?

Thanks as always for your guidance, brickboard folks.