2000 Freightliner fl80 fuel gauge not working

If the gauge is making the full sweep, then there’s a good chance that’s not you problem.

Probably a break in the wire between your tank and the dash.

 

New sender was $60 for my fld...if yours hasnt been changed in 18 years, I'd try that

 

Take the fuel sender out of the tank... from there, leave it plugged in, work the float around, and see if the gauge moves with it. If it doesn't, you can validate that finding by ohming out the sender.

 

Not yet, if you can find the pin in the back side of the cluster and ohm out the wire, then you’ll have it narrowed to the cluster

 

I really expected you to find something wrong in the wiring, sorry I asked you to dig so deep. because the gauge made it’s sweep when the key is turned on, I didn’t think it would be the issue.

You’ve checked your sender and the wiring. I wouldn’t think there would be a separate fuse or power wire feeding just the fuel gauge in the cluster. So it must be the cluster.

If it where mine, i would tinker with the cluster, but I also spend more time than most trying not to spend money!!! I would take the cluster apart to where I could look at the circuit board and look for a cracked solder, broken wire, or burnt circuit board and either confirm its failed and try to rig it back together.
But then again, you maybe sick of it and just be ready to be done!!!