I have a 1994 Oldsmobile bravada the fuel gauge reads full constantly why?

usually when that happens,it is the fuel pump sending unit.it's bad, the float arm/switch goes bad.it's all in the fuel tank.3 choices,if you can live with it,use the trip button on the odometer to keep up with the miles,cause the fuel pump is still working.go fill it up,reset trip.if you get 350 miles to a tank,go fill it back up when you put 275 miles on it,reset trip again. or you can replace just the sending unit,$60.00-$85.00.or replace the whole module,fuel pump and sender for $100.00...either way on the last 2 options,tank has to be dropped.if you decide to replace,run fuel tank low. Delphi/Fuel Pump, Part Number: DHP10004 Delphi/Fuel Pump Price: $91.99 plus tax Part Number: DHP10004 Actual OE Part Warranty: Limited Lifetime Notes: Fuel pump and sender Actual OE Part

very poss fuel tank sender is bad