Hello, I have a 2003 F350 regular cab Long bed. I does have a 12v cummins in it but I don't think that would change the speedometer any. It just doesn't work at all. I have replaced the sensor in the rear end. I know there is a sensor in each hub up front. I am not that familiar with what sensors do what. I would really love to get this fixed. Thanks in advance.

 

Sounds like a wiring issue. The sensors up front are only for the ABS not the speedo.

 

Is there a spot where I could get a copy of the wiring schematics for this truck? If I knew where the wires went and what colors they were I could check them for continuity. Thanks

 

Ebay has Ford OEM wiring manuals for sale.