Electrical problems probably Lima. How do I still get light?

Hello. With my Suzuki Katana AY50W (old series) the Lima, more precisely the pole wheel is probably defective. E-starter, brake light, turn signal and horn work. However, coils are probably broken which were responsible for front and rear light, tacho lighting and tank indicator. Anyway, the workshop told me that!? I read now that rectifiers can also break. I measured for myself, the measuring device shows with both cables from the Lima with connection to the cable tree at running Engine fluctuating between 0 and 4 volts AC. If I disconnect the connection the engine goes off. A new rotor is too expensive for me (200 €) and used there is nothing. So that I at least have front and rear light again available (only from time to time when I drive in the evening), I would like to have the juice removed from the battery instead of from the Lima. In doing so I would take in buying the battery more often to recharge. But how do I wire that? Bzw. is this the right way? From the Lima go a red and a yellow cable to the wire harness. There they disappear. I have a separate light switch on which there are three cables, but no red and no yellow what comes from the Lima. I have already tried to connect the +Pol of the battery directly to the red or yellow cable, since I thought one of the two would work. However, after pressing the switch the light remained out, even with running motor. Can someone help me?