Originally Posted by phunk

Attached a piece of the service manual for you.

I would start with, fill your tank again... then use the meter to test both level sensors to see which one isnt reading full. You can do this by just unplugging both of them and touching the contacts shown in the attachment. You dont even have to open the tank at this point.

This will at least show you which of the 2 sensors is not indicating full.

Then once you know which one it is, you want to burn off at least a half tank, then remove that sensor and test it on the bench to see why its not reading full.