6G Alternator Help!

I have the 6G Alt in my car, and at idle the volt meter needle likes to bounce up and down along with my idle but when I am cruising the needle stays at a solid 14V. My idle will only vary a little bit, maybe 50rpm, but my voltage will go from like 14V down to 11V and then bounce from 11V to 8V. Is the voltage regulator shot on the alternator? If so then why does it stay steady when I am cruising? Is my battery not good enough?

Thank you.

I checked the ground near the battery and it was fine, also I tightened the nut down on the back a lot and actually sandwiched a piece of metal in there because the connector is an oval so that it would touch the whole connector.

I am going to go check right now to see what color the regulator is.

Thanks.