Im not sure, but that would make sense. I dont recall ever seeing a separate fuel gauge for a diesel. Guys that do diesel conversions on there trucks still use the factory gauge.

Do you have one that is acting up? There is a fix posted on one of the diesel forums, either 1st Gen or Diesel Bombers.

It involves using a light spring to keep tension on the traveling arm to keep the fuel gauge reading. After time the pivot wears, and allows for a gap to form. Causing loss of reading, or inaccurate readings.