1985 Chevy Silverado C-20 4X4 fuel tank sending unit registering wrong

[OntimeG]

I have a 1985 Chevy Silverado C-20 4X4, that I replaced both tanks because of rust, sending units, tank switch under the bed, all of the fuel lines, the carburetor, the fuel pump, in dash fuel tank switch and I'm getting an empty tank reading on one tank and a full tank reading on the other tank even though both tanks have gas in them. Can anyone tell me what is the probable cause for the reading error?

 

[bucket]

Howdy from Ohio!

I'm assuming that neither tank is nearly empty and neither tank is near full? It sounds like the tank that shows full has a sender circuit that is grounded out and the other tank has an open sender circuit.

 

[bucket]

P.S. I moved this to the tech section.

 

[Shorty81]

Welcome from Ohio #2

 

[dvdswan]

Be sure all your grounds are clean and good. At the tanks, frame, and dash.