I think this is right way:
1) Leave off
2) Set on the ohms scale lowest setting
3) put red lead on solder point on the wii.
4) put Black lead on solder point on the wiikey thats connected by the same wire.
5) u should get a reading of no to very little resistance (which means that voltage/current can run through that wire whithout resistance, which is good)
RYZEN 5 2600|RADEON 570| |ASRock X370 Killer|DDR4@2800Mhz||Corsair SPEC-05 Case|AOC G2590FX 24.5''144hz 1ms|