No just a conventional series connection, positive to negative bridging and ground is common in whole frame and body as normally it is. No device or anything else that distinguish being 24v instead of 12v.
Just the applications are all 24v, bulbs, alt, starter, cluster,
Oil switch, edic motor, edic motor module.
Mostly people don't have sense of edic motor so they just hook a manual wire to diesel pump main linkage if they pull it from inside the jeep shuts off when I bought mine it was like this. However I prefer when we switch off the jeep turns off itself.
Plus there's one beauty about it, oil pressure value is input to that edic motor module and incase if oil pipe bursts or for some reason oil pressure drops the edic motor starts pulling off the pump linkage to switch off position again and again and if you turn it off then it doesn't switches on. Very beautiful piece of safety check in 1980's