Electrical Issue

[imZiRT]

13 Sierra 2500HD SLE, 6.0flex, crew cab 4x4.....
Issue is, occasionally, engine running,  instrument panel warning lights all come on, gauges all sweep full on to full off then to normal, HVAC glitches to blank then sets temp to 74F, AC on, Passenger temp button light on, auto door locks unlock, info center in odometer area switches to trans temp or something other than the odo where it would normally be..... after the initial freakout, the warning lights go out, gauges to normal, everything good (except the HVAC stays at 74* with AC on, etc) - in a nutshell, everything in the dash (interior? body?) seems to "glitch/reset".  I think I've narrowed the problem down to occurring when I've tried to put the power windows up more than one at a time, like I pull both rear or both front window switches up at the same time- boom, everything goes blippy. No codes in any system.
I'm thinking one of two things: 1) The power window(s) are pulling too much current for some reason and it's causing the cluster and BCM to spaz, or b) There's a bad ground somewhere that pops up when the windows are operated simultaneously. I don't have a scope, but I could check battery/system voltage while trying to duplicate (if I can get the wife to help out!).
Hit me with your thoughts...

[richard wysong]

Bad connection at the battery or distribution panel would be where I would check first but it may also be a battery on its way out, have it load tested. Bad ground is also a possibility affecting the BCM

[imZiRT]

42 minutes ago, richard wysong said:

Bad connection at the battery or distribution panel would be where I would check first but it may also be a battery on its way out, have it load tested. Bad ground is also a possibility affecting the BCM

Dual batteries, both +/- 2 years old (not that age is a guarantee...), and all connections were serviced a few months ago (again, not a guarantee). Alternator is less than 1 year old.
I'll make sure to test them and check connections.