2007 GMC Sierra electrical issues.

[Ned]

My 2007 GMC Sierra recently started acting up. The instrument cluster goes all wonky, it says service 4 wheel drive, service stabilitrak, The gauges bounce all over the place or stay at no reading, my door locks attempt to lock and unlocks, abs light comes on and it seems to have started to shift harder. I feel like it’s all one issue but I’m not sure where to start.  Any help would be much appreciated

[muddkatt]

Start with the ground(s).