On my trip back from Corpus Christi my gas gauge is not indicating correctly, shows 1/2 or 1/4 full after I've filled the tank...but the reserve light is operating correctly. I'm sure there's a thread on this but my search worked as well as my gas gauge

float is not returning to the top as the slider rod is corroded, remove the sending unit dismantle and sand the slider rod until the float runs up and down easily

well, could be a few things.
All require you to remove the expansion tank, and then the fuel level sending unit in the top of the tank (lots of little bolts)

Could be:
1) sender electronics are bad (check with a multimeter)
2) float is cracked (get a new sender)
3) rod that float is on is crusty and float is stuck (clean everything)

Test is if the float is bad by making sure there is no fluid iin it, and submerse it in water, look for bubbles.

Rich

George is watching, or Dave knows.
I forget the voltage range, but I seem to recall its .5 volts top to bottom that will change the meter when you test it with the multimeter.

Ahh yes... the humidity down here absolutely kills the slider / float movement. I always have a clean spare on the shelf...
The easiest method I have found to restore functionality is a good overnight soaking in CLR.
No need for disassembly. Just shake it lightly a few times to insure the free movement of the float.
Good luck.

OK, thanks. I just refilled the tank so I'd best burn some fuel before repairs.

Check the resistance on the sender as you move the float up and down. Should go from around 0 to 90 ohms. I’d agree that cleaning the sliders should correct your issue.

What I also do is re-set my odometer trip meter to zero every time I fill up. At 300 miles, I need to be looking for a fuel stop.

Had the same problem Did all the recommended stuff. Went as far as getting a new sending unit, only to discover my gauge was bad. Soooo, lesson learned? It's not always the assumed problem.
Check your gauge. Me, I had a spare one and compared the two (hooked up). My spare read dead on, the original? Same exact problem you've described.

Plus 1 on this... I do the same.

I just replaced the bladder in my fuel cell and the float tube on the sender is quite loose. Read "wiggly loose" Are going to R&R the sender: disassemble, clean, reassemble... hopefully that will work. I have seen a good thread on the 911 bird board about this.