Back light

Hi all, is it correct that the back light is powered by the coils, only the back light nothing else, thanks

...on 1979 MY only the headlight I think.

There are two coils one does the ignition which is the one one the left and the one on right does the lights horn and charging.you can run the bike one one coil with no battery if you want but you’ll have no lights ect,hope this helps.