Strange electrical problem (dimming lights, losing power)

[FreckyB]

I have a 2008 Silverado LT, with a Kenwood 9980HD head unit, and JL 13w5 sub, I have had the sub and amp in the truck for 2-3 years but within the last week or two I have been having some problems with my head unit shutting down and resetting when I use too much electrical in my truck (turn on my high beams, roll up the windows, turn on the signal lights, when stabilitrak activates) the headlights dim for a second, the HU resets, and yesterday it got worse to the point where a warning popped up saying "stabilitrak off" and all of my gauges went to zero for about 5 seconds when I began to lose traction on the icy highway, so I am guessing that power was being pushed to the traction control and that caused it. My battery gauge on the dash is sitting around 14 sometimes slightly higher sometimes slightly lower (not really sure what it is normally it's not really something I pay much attention to), I was just wondering what could be causing this? I am hoping my battery is just going as it is the original one from the factory. It really began to worry me when I my stabilitrak turned off when I lost traction as it stopped being a minor annoyance and started being a safety issue.

Any help you guys can offer is greatly appreciated.

Thank you