Phaeton :: Dash Lights Flicker Sometimes While The Engine Is Running

The issue being that my interior, tail and sometimes dash lights have begun to flicker while the engine is running. It's noticeably worse upon cold start, however, once the engine warms up the flickering improves a bit. Also noteworthy, is just after starting the voltmeter jumps around between 14-14.5 volts. When the car idles down it settles at 14. My left side battery is sitting at 5 years old and when just the electronics are on it hovers around 13 volts. Am I looking at a failing alternator or voltage reg? Or perhaps a loose connection or iffy fuse or ground somewhere. The car does not idle roughly and I am not hearing or smelling anything that isn't normal. I just had both vcg, valve body, and tie rod ends done. I do not have a vag yet, but I was wondering if there is any for of troubleshooting I can do before she goes back in?