I just purchased a 1996 Ram 3500 dually with 5.9 cummins, there are a lot of "little" things I want to take care of as I fix up My Baby. First the fuel gauge does not work and the fuel light is always on. What should I try 1st?
Thank you,
David

 

2 things. Either the sending unit is bad, or the float is hitting the side of the tank and isn't reading accurately. Fill the tank with gas, pull the bed off (much easier than dropping the tank) and loosen the giant plastic nut that holds the pump/sending unit in place. Rotate the whole assembly just a tiny bit in either direction and see if your fuel gauge jumps up.

*Edit: A 1 ton cummins might be set up a little different, I'm not sure if this will work in your case.