Man, I am gonna follow this thread because I have the same issue. I checked the following on my bike so far: Continuity from lighting wire to taillight, continuity of ground wire in rear fender, clean connections, good tight connections at terminal block to lighting coil wire from magneto, double ckecked brake switches, new bulbs. So far, still no lights. At most, got the taillight flickering for a spell, then nothing again. Check what others have suggested last month about this same problem. Hope you have better luck than I so far. Last suggestion was to check voltage at light coil wire from magneto with engine running. I am still wondering if the lighting coil per se is dead.