Wiring diagrams are a handy start, failing that it’s a case of following the wires/ disconnecting everything and checking wires with continuity tester, good luck, why do u need to trace them? I had to do this to remove an alarm from a motor bike and boy it’s a headache as all 11 of um were black with no diagram available
Its reading to me that you’re wanting to add a switch on the steering wheel. The issue you’re going to face it all the factory fitted wiring goes the the slip ring behind the steering wheel. Copper strips wound round i a coil which allows for the steering wheel to go lock to lock whilst still having wiring and switches to the wheel, the horn and airbag also go through this. Word of warning though, if you’ve already got the wheel off, dont turn the slip ring by hand.