Just bought an 86 k10 silverado, the fuel guage will only read a 1/4 tank when both tanks are full, what could cause this. I am new to the forum and working on vehicles any information will be appreciated.

 

You may need to have your fuel tank dropped and replace the fuel bobber.
I had this problem with another vehicle of mine and the bobber inside the gas tank
was messed up. probably a 99% chance that is the problem AFAIC.

 

I thought that to but it has duel tanks I guess both floats could be bad.

 

it reads the same with both tanks? could be the "bobbers", could be the gauge, could be bad wire or connection.