When I bought my K100RT it had electrical problems, the speedo did not work all the time and the pass light didn’t work until a bypass was wired from the offside switch. I was told about the connections on the right hand side of the bike and checked they were clean. The other day the speedo stopped working and the oil warning light came on. Behind the instrument cluster there were some broken wires and a couple that had been twisted together. 
I decided to replace the connectors and used butt connections and bullet connections to join the new plugs. One of the wires that had been twisted together and wrapped in electrical tape, was the oil warning light. I went for a ride and everything worked properly, I did have a problem with the front marker light, it only worked with one bulb but not a new bulb, I switched the wires around and now the lamp works with LED’s. Now I need to find time to trace the wiring fault on the left hand switch, I expect it is in the wiring loom between the right hand switch and the left hand switch. 
By fixing the more obvious fault, it seems I have cured two faults that seemed unrelated.