FLD120 Odometer Not Working?

If speedo is working fine I would say you have a problem in the speedo head itself.

 

If/When you replace your speedometer. Make sure the small switches in the make match.
Good luck

 

Wow....I wonder if someone turned the odometer back, you do have a record of the Odometer from previous title transfers, Eh ?

 

All the above are correct. One fleet I worked for had us open up the new speedos and set the mileage to the estimated correct mileage. From that and some used car experience that is a sign that it has been tampered with. Another is if all the numbers do not line up correctly. Sometimes finger prints show up on the face later or the white is discolored. Not many people can change a mechanical odometer correctly. The head could have just had a problem. Hope you did not pay big bucks based on low mileage.

 

Are you aware that the truck / engine keeps a lot of information on the ecm? These units have performance monitors connected to the transmission. The ECM can retain mileage from date of install. Here is a printout of what data is collected, including top speed. Notice the odometer reading in the top right heading...93692.5 mi. You can have a shop poll your data and get the mileage too.

 

What if the ecm was replaced.

 

The Certified Detroit Diesel Tech has reprogramming software designed to update the new ECM with Vehicle Id, engine ID, ..... odometer reading when replacing a faulty DDEC.

 

Yes and just set all the toggles the same as mentioned. That does just happen sometimes.