When the tank is full on my Dakota, the only way to get the correct level is to turn the key on with it not running. Once it starts and i'm driving, it normally sits on the E peg unless i hit a big bump then it jumps around...Once i get to 1/2 empty in the tank, the fuel gauge works properly and will until it gets to E. Not a big deal for me since i can still tell when i'm getting low, but was just curious as to why it is doing that. I figure the sending unit is worn out or something like that...guess i'll just live with it until it fails completely.

 

if the sending unit is bad will the light still work? My gauge is peged on full and have not tried to see if the light will come on. Guess i will carry 5 full gal gas can and try it>>>have a 90 LE extended cab 3.9 how do i tell my gas tank size?

 

Im wondering if your floater got stuck against the tank on the top half some how? I have heard of it happening before. Somehow the pump shifts and the floater gets stuck either at the top or the bottom showing full or empty.

Just a note... If the arm is totally off, it should show empty all the time lol.

 

ok so my truck is for sale right now and the only thing holding back on my buyer is that the gas gauge wont work. my gauge goes where it pleases and my gas light has never came on. is it more probable that its has something to do with the dash than the sender unit? or are the gauge and light not conected?
i always just use the trip but its going to a teenager who wont be filling the tank every time. the buyer would be happy if the light at least came on how can i check it?
by the way perfect timing on this thread

 

Check your wiring
Check resistance output from pump harness for readings. (ohms)
Remove tank and see if there is something wrong with your floater.
Sender unit or gauge could be defective...

 

If your gauge is bouncing around. whenever it wants too. I would start at the gauge itself and track the connections and wiring.

 

yeah. my truck has a low fuel like... but my gauge wasnt working because the sending unit was fried. replaced everything in the tank.. works brand new... the little circuit board was all fried and black.

 

Which circuit board is for the low fuel? Isn't there 2?

 

*shrugs* i'm not sure.. the one that the float level on the sendinng unit ...

 

There is one board, and its on the pump. I will see if I can find the pics. They were on my web link earlier. The floater arm and circuit board work as a potentiometer telling the gauge what level its at with voltage/resistance levels.