You seem to be saying that the voltage by your multimeter is not steady with the vehicle running, yet it is steady by the dash gauge. Have I got that right?
I would get a second opinion via another multimeter. One of them is lying to you.

 

I have checked the multimeter on a different vehicle and it's fine. I have solid connections all the way up to the c100 clip. Going to clean that up and go from there into the jeep. I'm pretty confident now that it's just a loose connection somewhere. Fingers crossed I get it fixed today after work. I will definitely post on this thread if I get it solved. Haven't been able to find any info for this same problem anywhere.

 

I'll bite, whats a c100 clip?

 

It's the main clip that goes through the firewall on the drivers side. Backside of the fuse panel.