Barditch......On both sides of the coach, just behind the front wheels, you have two panels, one on each side, that has the fuel fill door in the center. If you look under the panel on the left side, it has two tabs with screws in them. Remove the screws and lift the panel up. It's hinged at the top. Inside you'll see the Centroid fuel sending unit. Multiple wires connected to it.
What is your issue. The Centroid unit is adjustable with set screws.
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab