2013 T660 electrical problem

I'm having strange intermittent electrical issues with my truck.
MX13 with 13sp

What I have is while driving the DEF gauge will drop to 0 and light will flash with dash saying low def.
Dealer says probably level sensor. But I'm leaning towards a bad ground or connection somewhere. Reason I say this is when its happening it starts picking up codes until I'm showing anywhere from 6 to 8 codes. Then as gauge starts climbing the codes disappear.
Sometimes I can go a full day with no issues and other times every couple of minutes its doing this. Of course when I have it home to diagnose it, it wont screw up.
Would love to fix it before it has to be towed in.
I'm just hoping that there is a couple common places to look for a bad plug, rub through area, or ground..
This is my only truck and cant afford to much down time right now since it the busy season for propane.

Any and all help would be greatly appreciated.