You may need to physically move the start/stop fuel cutoff solenoid into the off position.
I don't know your machine, but should be easy to find in the fuel line somewhere close to the injection pump. Probably has 2 small wires going to it.
(had that happen to my TG1860 one time and it freaked me out)..pulled every fuse and no help !
If you let it run out of diesel, you'll have a whole host of new problems.(in addition to your current electrical problem)