Fuel gauge

[davebar]

Question about the fuel gauge. Did a search and couldnt find an answer.

When I have a 1/4 tank, the gauge will go to E or bellow when going down a hill and go back up to 1/4 tank when going up hill. Is this normal? I know it fluctuates some, but that seems to be abit much.

 

[Surrey]

Be happy that it reads at all. Many of us have problems with our gas gauges not reading anything...

 

[Earl43P]

That is a bit much.
Your sender operates from 22 ohms=Empty to 145ohms=Full.

Your symptom can be caused by the float filling with fuel.
It is probably the classic bronze float with corrosion holes.

They run about $8 at the Ford dealer.
Many aftermarket sender floats are plastic and don't have that problem.

Access is always the stickler. Most folks remove the bed to get to the top of the tank.
For that you need a T55 bit and a breaker bar. Remove the 3 small bolts at the filler door panel and disconnect the tail lights harness at the rear bumper. Some simply tilt the bed enough to gain access, which should suffice.

For your year, the wires are YE/WH and BK/OR (ground) at the connector atop the tank. If you short those two wires together, then turn the key on long enough to read the gage it should read empty. The anti-slosh module in the instrument cluster is supposed to dampen out gage fluctuations. My guess is that your sender float is full of fuel and fluctuating more than the slosh module can electrically compensate for.

My 2000 had similar behavior, but not nearly that great. Long downhills would cause a lower reading but nowhere near 1/4 tank of fluctuation! More like a single tick mark on the gage when nearly empty. I used to regularly run that truck down into and below the red zone and still have more than a gallon in the tank at fillup.