Hello, here is a diagnostic sheet for your truck, due to problems with system Ford sent oput this quick check sheet for techs to use. Let me know what you find. Thanks
This article supersedes TSB 07-9-2 to update the Service Procedure.
Some 2004-2008 F-Super Duty 650-750 vehicles equipped with dual fuel tanks, may exhibit one tank emptying and the other tank remaining full.
Follow the Service Procedure steps to correct the condition.
On 2004-2007 F-Super Duty 650-750 vehicles the right fuel tank will be empty and fuel does not transfer from the left tank.
On 2008 F-Super Duty 650-750 vehicles the left fuel tank will be empty and fuel does not transfer from the right tank.
At Connector C3264 (2005-2008), C9102a (2004), located at the fuel transfer pump, perform the following: