rear light,

[thenutt]

gas gas ec250 2002 model,
for some reason or other my back light keeps going. if it aint the brake light element in the bulb going it's the tail light element going, this is happening on a regular occurance,
has anyone got any ides, i was told to fit a rectifier from the coil to the back light, so it will reduce the power going to the tail light, if this is the way to fix it, anyone know how, as i'm useless at wiring