Have you downloaded the TM's? Yes
Have you tried looking at the troubleshooting diagram?
Yes
Is this gen set new to you? Yes
Or have you seen it work right? No, bought not running, supposedly pickled but I’m pretty sure they would not have left diesel in the tank.
Can you read schematics? Auto and diesel tech on the side, but not a electrical specialist
What is a "dead man switch"? The switch right by the injection pump. Has 24v in and 24v out with the switch on or off. (This should be the S22 dead crank switch)
yes, you should have 24 volts at the L4 fuel cutoff solenoid. On both studs? (how did you mesure this? One wire is hot, (P86A) one wire, (P55X) is ground. When I measure at this place, I take the wires off. Measure VDC from a good ground to wire P86A, with the S2, (engine start switch) in the Start position, you should get 24 VDC. Measure Ohms from a good ground to wire P55X. Should get continuity. If you still have the top of the IP, (L1, fuel cut off solenoid) off, hook wires P55X and P86A back up. Holding the L1 in your hand, have someone turn S2 to the start position. The small "flapper" should move. It is to open and close the fuel going into the IP. Try this and let us know what happens. while the I’m used to a Cummins with a pull wire, hold wire, and a ground.