Electrical problems

[FsuMatt]

I have a 2010 GMC Sierra z71 4x4 in need of an exorcism, hopefully yall can help. Recently while driving the truck will go crazy,  the locks will lock and unlock, the ac goes crazy and the transmission will go out. It's like putting it in neutral,  the rpm gauge will move but the truck is not going any faster. So I will pull over turn the truck off and it fires right up with no problem.  It throws no codes,nothing. I've checked the the wires on the battery, they are good and tight, yesterday I crawled under the truck to locate grounds, and the one I found was tight, I did take it off and clean it. Any help would be appreciated.  I do have a buddy at the local chevy dealership,  I talked with him and his response was unless it throws a code we would be chasing a ghost. 

[diyer2]

Good Battery?

Check every ground and battery cables.

Your buddy should be able to tell you where all the grounds are.

IMO

You have an electrical issue.

Low voltage or a short.