Hello, 

I have a 1978 Yamaha DT.  All lights are working except brake lights do not light up when I brake.  I have checked connections, bulb and the battery is new and still cannot fix this issue.  Any insight on the problem would be helpful. 

Thanks 

What about the switch,  down at the pedal,,,  2 wires,  the brown should have voltage [   key on,  ]   .pull the swith  with pliers , it may need adjustment, 

Tried the bulb!