fuel sender read full, when empty, help

[Wolverine]

Hombres:
So, I replaced the aux fuel sender and that unit works/reads fine. Now working on the main. Tank read empty, when actually full, so I check the wiring and... previous owner had the wiring flipped. I rewired and tank read full, and it, was so I thought 'fixed'. However the reading stayed full until I ran the tank dry. I'll take the sender out and check the float to ensure it isn't stuck (rusted). Any other ideas?

 

[DirtDonk]

Hmm, interesting one you got there Wolverine.
What happens if you just leave the sending unit disconnected? If it still pegs to full, then the issue is with the wiring or the switch on the dash.
Since the gauge works fine on the aux tank, then you know that at least the wiring is fine after the switch and the gauge is also fine.

Paul

 

[DirtDonk]

Oh, stock tank still, correct?

Paul

 

[Wolverine]

Paul:
If I disconnect, unit goes to empty. Fairly certain stock tank. I will take out sender tomorrow, and 'see' if the float is stuck.

 

[SteveL]

I remember having an issue like that years ago. Is there a ground off the sender or tank you need to attatch to the frame/crossmember.

 

[Wolverine]

Steve:
Yes, there is a ground, covered in thick undercoat. I will rewire/route that and test before I take the sending unit out. Thanks.

 

[Viperwolf1]

Are you sure you don't have the wiring flipped at the tank? Orange wire to ground will make the gauge read full.