Fuel gauge reads full all the time

[Gill7858]

Hello all, I have a 2006 26 ft center console with a 250 hp 2002 ox66 2 stroke. My gauges have been working fine but for the last three small trips I've taken, it keeps reading the fuel as full and on the same gauge the speed fluctuates (I'd be traveling at 30knts and it reads 8knts). Is the gauge going bad and how can I troubleshoot this? Thanks

[joe009]

look at the top of the fuel tank, there should be a wire connected to the sending unit on top of the tank.disconnect the wire from the sending unit.the fuel gauge should read empty.if it does not, there is a ground on that wire.if the gauge does read empty the sending unit is bad.

[Gill7858]

Ok I'm a little confused. If I disconnect the wire it should read empty,right? If it doesn't read empty, then what about the ground?