Voltage reading problem

[ftwflh]

My 2012 Tahoe LT has been showing 14v or a little higher on the gauge.Today it started to drop about a 1/4in or more on the gauge.Never got out of the white area.But when I shut it off and restart it it goes back to normal a little past 14v. Run it and it drops down.
I have put a volt meter on the battery and with the key off it shows 12.5v start it and it goes to 14.2v then slowly drops to 13.1v or a little less.Start it again and drive it it does ok for awhile then acts up.
I am leaning towards a faulty regulator/alternator. Truck just turned over 100k so what does everyone else think?

 

[Doubeleive]

sounds like normal operation, these trucks have a voltage regulation system (rvc), you may notice the round voltage sensor attached on the ground cable to the right of the battery

 

[ftwflh]

sounds like normal operation, these trucks have a voltage regulation system (rvc), you may notice the round voltage sensor attached on the ground cable to the right of the battery

If it is normal why am I just noticing it?Any other Vehicle holds a steady volt reading and doesnt fluctuate.

 

[Doubeleive]

If it is normal why am I just noticing it?Any other Vehicle holds a steady volt reading and doesnt fluctuate.

welcome to gm's version of saving energy, the RVC system regulates the alternator output to better manage the battery and supposedly saves on fuel economy (I don't see how) but that's what they claim. Me, you and many others were initially perplexed by this same system

 

[Doubeleive]

in fact when mine started not fluctuating (like it normally does) I questioned why it wasn't working the way it should, shortly after the alternator died

 

[ftwflh]

Got it lined out today.Took it in to AZ and had the charging system checked.Showed bad ALT not regulating voltage.Changed it out and all is good.Charges 14.6 going down the road and drops to 13.8 in traffic with AC going.Comes right back to 14-14.6 once going.