2012 sierra, headlights flicker

[MrBooger]

I have a 2012 sierra, 5.3 cc z71. Is it normal for the headlights to flicker, and it's a good flicker, when the a/c cuts on or off? It happens while at idle and when driving. I also noticed, when at idle if i press the brake, i can see the interior dome lights slightly dim. voltage guage shows correct.

[MikeNH]

It's normal. The alternators are designed to out out minimal current to increase fuel efficiency but this is what happens. You'll also see them dim if the ABS/traction control/stabilitrac kicks in.