Help with fuel gauge

[Yamacajun]

Fuel gauge stays on full when key is turned on.
Drops to zero with power off.
Factory seapro set up with onboard tank.
Yamaha 90 outboard.
Can someone tell me how to troubleshoot this?

Thanks

[rodbolt17]

that is how it works.
is the tank actually full?

[Yamacajun]

that is how it works.
is the tank actually full?

30 gallon tank.
I have filled it up and made 2 half day fishing trips and it never drops off of pegged on full.
As stated if powered up it never leaves full.
Boat has been parked with full tank for a couple months sometimes.
Could the arm in the tank be frozen in the up position?
Or am I barking up the wrong tree.
Not sure where to start troubleshooting this.

[TownsendsFJR1300]

30 gallon tank.
I have filled it up and made 2 half day fishing trips and it never drops off of pegged on full.
As stated if powered up it never leaves full.
Boat has been parked with full tank for a couple months sometimes.
Could the arm in the tank be frozen in the up position?
Or am I barking up the wrong tree.
Not sure where to start troubleshooting this.

If it's not moving with several trips, sounds like the unit (in the tank) is either stuck or simply bad. The gauge in the dash is working as it goes up when powered up...

Pull the unit from the tank and inspect/replace...

You can hook it back up once out, slide/move the float and see what the dash
gauge does. Obviously it should move as the float(etc) goes up and down.

[Yamacajun]

If it's not moving with several trips, sounds like the unit (in the tank) is either stuck or simply bad. The gauge in the dash is working as it goes up when powered up...

Pull the unit from the tank and inspect/replace...

You can hook it back up once out, slide/move the float and see what the dash
gauge does. Obviously it should move as the float(etc) goes up and down.

Thanks for the info. Started to pull sender once before and stopped.
Will open it up and see what I find.