How does transfer box 4x4 work ?


I've removed the body off my rotten Fourtrak (1988 / E reg) with the intention of fitting the engine and gearbox into my CJ-5 Jeep.
The transfer box wiring / pipes are a little confusing.
I assume the drive to the front axle is vacuum operated.
Am I right in thinking that it works by DISCONNECTING the drive when engine running and drops back into connected when stationary Unknw
What are all the wiring sensors / switches for Unknw
I can understand reversing lights and low range (so that front drive automatically selected) but what are the other two switches for Unknw


Paul Humphries.