The '78 does NOT have a headlight switch, so I'm guessing that's what the PO did.
I have half a mind to figure out how to do the same, since it would take a load off the battery when starting. The other half of my mind, says just figure out how to get it running 100% stock, since I'm so close to getting it there.
Riding my airhead is like eating chinese food . . . an hour later, I need to ride again.
1978 BMW R100S "bitza" (R80/7 frame)