fuel gauge problem

[SDakDmax]

I have a 2001 extended cab short box. When the tank is full the gauge will show full, then it will go to empty and the low fuel light will come on. After about 10 seconds it will go back to full. It will do this off and on until the tank is close to 1/2. then all is well. Does this sound like the sending unit? If so what is the best way to get to it. drop the tank or lift the box? I noticed in another thread someone said to put a good dose of sea foam? I usually don't have much luck with anything like that working, seems like new parts is what it takes. Thanks for any advise that I can get.

[cowboywildbill]

Sounds like some gunk on the sending unit. Or it has a dead spot on it. They are basically just a reostat/potentiometer, I'm sure I screwed the spelling on that!. At least they used to be. It could be a bad guage also. You can ground the sending unit wire and if the guage goes to full and stays, then it is most likely the sending unit.
It is likely mounted in the top of the tank and you would have to drop it down and maybe take it out to get at it. Just make sure it's near empty if you do drop it. Makes it lot's easier and safer. I'm sure one of the techs will know. Good luck.

[More Power]

The following forum thread has some good info that is useful for troubleshooting a fuel tank sender.

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=23491

Jim

[SDakDmax]

thanks for the reply Jim, Always glad I'm a member to The Diesel Page. Best money I spend. I'll get my ohm meter out and check this. I did find this site for sending units. www.tristarrradiator.com or search tri-starr sending unit. i think it was abut $89.00 Thanks again ,,,,