voltage gauge ticking

[chevy joe]

think its the alternator but not sure. just sitting in it last night with it running the volt gauge was ticking up and down @ a volt like a turn signal (turn signals were not on) i could see the voltage change in the dome and headlights. if i turned on the brights and put my foot on the brake it would stop. seemed to only do it under 1000 rpm also. didnt notice anything going down the road. anyone else had this happen?
*edit* almost forgot the battery light was very lightly flickering when the voltage would go down. it never dropped below @ 14.3 v on my digital display

[alberta 7.3]

Most likely the brushes are worn out on the alternator.