Gday ,
            The recent abay acquisition k100 has turned up a wiring harness worn through an active wire as it exits the box and ducks under the frame, some hot wires and melted insulator
So ,  question being, will an 84 rt harness swap and operate an 86 rt.
I see a difference in the injectors,  another device on the return rail , a pressure switch or pressure transducer ?   All the fuse and relay box look identical ,  any knowers appreciated
Ñ.

the 84 s had a vacume sensor on the return rail mate ....deleted in later models after 85
should be ok to disconnect this .
the rest of the loom should be fine ....just depends on the accessories you have fitted

save the old loom though ....some blokes could repair it I guess

It would also be some different connectors here and there.
Fuel tank, ignition switch, GPI switch, and between engine/frame harness.

oops yeah the fuel tank could be in a different location  that's a bummer
gpi would be different inge ? hadn't thought about it ...!

On the later models these four mentioned connectors is all of the same type.
On the earlier models a different type of connector is used.
Three of them is of one type, but tank is different...but that it's the same as the alarm connector in the relay box.

splendid observations inge ...^5s

Thank you both for that , saved me jumping in boots and all again!