I know that‘s not in question format, but I have a Honda Rebel motorcycle, the tail light consists of one bulb which still works when the brake is depressed, but that‘s all, even when the lights are on. Could this mean I need a new bulb, or is there the dreaded yet oh so fabulous electrical problem going on here?
The bulb has two filaments--one for brake, one for tail. One filament is most likely burned out. Buy a replacement, and a spare.
if the bulb's filament is in tact, try to have a look at the Brake switch generally attached to the brake peddal with a long spring, it would need to be replaced