Is their a write up anywhere for this DIY repair?old forum lol... have you checked to make sure your gauge is working?
with the key on acc. (dont start it) but have power on...
unplug the wire thats on top of your fuel tank. the fuel gauge should go down past the empty. then connect just the two middle wires. the gauge should go all the way to full. if it does this then its working.
also check the fuel gauge wiring along the frame running up to the gauge cluster. make sure all the connectors are clean and not dirty. i seen on some forums where people said that the wire for the fuel gauge was melted to the frame.
Dodge Manuals and Reference Books-Dodge Cummins Diesel Truck Accessories – Geno’s GarageA very good investment is the $30 service manual cd from genos. Tells you how and what to test for the fuel gauge.