cezonetheillest

well my fuel gauge has never worked unless i just filled the tank full. so i am driving yesterday and all of a sudden it starts to work so i am like cool. all while i was looking at that i almost ran a stop sign and slammed the breaks. so then i look at the gauge again and it was all of the way down then it started to go back up. could this just be a possible ground wire(i have no clue how the sender works). any help would be great so i can for once and all know how much gas i have.