Anybody have one that actually works? Mine read full the whole way down to Hilton Head this weekend, but it took 28 gallons to fill up. Even when it was just sitting in the harbor idleing it reads full… Last summer it would move and seemed to be fairly accurate. I filled up the beginning of this summer and it has read full ever since. It does drop to empty when I switch off 
Mine hasn’t worked right since i’ve owned the boat & the previous owner fought with it as well. I have figured it out somewhat as far as what the gauge says now. Its an uneasy feeling the 1st time its blinking low fuel & you are leaving the G-town hole & you make it home with 20gals left.
21 Contender
I was comfortable with mine last summer, but now it seems to only read full… float may be stuck?
“Crawfish”
2008 Sea Fox 197 CC
2008 Suzuki 140
Mine didnt work when i bought the boat so put a new sending unit/float in it and it still doesnt work. reads full all the time i guess its the gague for mine.
06 sea pro 1900sv
06 14ft Alumnacraft
Wishin’ i was fishin’
Replaced mine a couple years ago. Works fine now. I stole these words from another site. Hope it gets you started in the right direction.
“Bottom line: connecting the wire that usually goes to the fuel sender to GROUND will normally give you a “FULL” indication. Disconnecting the wire completely will normally give an “EMPTY” or below-empty indication. If your display gauge acts that way, it probably is OK. If it does not, the sender is suspect. And if you suspect the wiring, then disconnect it at the gauge, and test with OPEN and GROUND to the gauge.”
So, if the gauge reads full and you disconnect the positive lead, it should drop down to empty. In that case the gauge is probably good and you have a problem with the sender. The worst problem with replacing the sender is the fear that you will drop one of the screws into the gas tank.