you could check the connection points (back of switch and sending unit on tank)
if everything all tight then one of 3 things
- broken wire
- bad gauge
- bad sending unit
if it were me; i'd add it to the list of fixes for the warranty claim to happen after you get a few trips under your belt; i'm guessing you'll find some other surprises along the way
2000 Volvo 610
2013 Cyclone 3950