Hi guys, I have a question about my fuel level sending units, I have a 87 f150 with mechanical fuel pump and dual tanks, both have 8 volts running to them and both of them worked when I put them up in a empty gas tank, but I put 5 gallons of gas in each and after that they still had volts runnin to them but they both act like they don't have a ground and both go way past full, keep in mind both worked before gas was added, anyone know? I can answer anything else if you need to know...thanks

 

Since five gallons reads as E on mine my only thought would be that they are upside down, don't know if that's possible but it is my only guess.