I have a 2004 F150 XLT 5.4 L 79,000 miles. Yesterday i was driving home turned a corner and the low fuel light came on and the fuel guage is well below empty. I had approx 1/2 tank of fuel when it happened. I have since filled tank all the way but the guage will not move and low fuel light stays on. Everything else is working fine! I have never run the truck low enough on fuel to make the dummy light come on.....any ideas?????????? thx!!!

 

fuel sensor maybe?

 

I have an 04 FX4 with the same problem. I have it at the dealer now, there was a TSB on the fuel sending unit so they changed it but my gauge still doesn't work. Hopefully they will trouble shoot it CORRECTLY tomorrow and I will post what they found when it's fixed correctly.

 

Is it flex fuel? there is an AC/DC convertor at the fuel tank to convert the voltage sent from the instrument cluster. It needs to receive power to work, could be a concern w/ 1 of 3 connectors located on the driver's side frame rail(known for corroding).

 

Thanks Wilber, no my truck is not a flex fuel. They told me that they are going to check the wiring harness to see if that is my problem.

 

Good call Wilber15, I got my truck back today and there were a couple terminals that needed to be replaced. Fuel gauge working fine now. I got a free fuel sending unit b/c of the mis-diagnostic check they did when they changed the fuel sending unit when that wasn't the problem. You would think they would check the wiring first, maybe next time they will. Thanks for the info and I hope this helps other people out there that have this same problem.