@axel, thanks for the parts list. 
Any chance you also have some European models manual? 
Thanks✌️

Axel, thanks for displaying the parts list that showed the dummy load resistor. Nixt as I said loads of good people piling in to help with your queries which is what makes this a great forum for info.  Although the attached wiring diagram is NOT specific to your bike it does hopefully help in showing what ‘your’ infamous resistor was designed to achieve.  The resistor is shown as component No 7 on the diagram.  When just the bikes ‘running’ lights are on (i.e. tail light, clock back lights) and the headlight switch component No 14 is selected OFF, the resistor circuit is energised to mimic the headlight load and hence establish the whole lighting circuit to be in a balanced condition with the bikes charging system.  When you turn ON the headlight circuit via switch 14 introducing a big additional load, simultaneously the resistor circuit actually becomes open circuit i.e. it is now out of service.  The nett effect of this changeover is a smooth bumpless transfer of electrical loads such that the charging circuit doesn’t detect any change. Anyway as I and  one or two others previously mentioned you want to scrap it in favour of a much more reliable modern and robust single wire voltage regulator.  The regulator needs to be bolted directly to the bikes metal frame (scratch the paint off wherever you decide to bolt it) to get a good earth and then splice the single wire into the lighting wire from your bikes stator going up to the main key switch.  It’s probably a yellow wire but I’m loathe to actually say it definitely will be without seeing a 1973 RT360 wiring diagram.  Perhaps others could comment on the correct wire colour?  Hope this helps. Andy.
 

Thanks Andy.

Single wire regulator gets spliced into the blue wires (from clock illumination lamps) in the headlight bucket - relevant service bulletin attached.