[Taurus]

Try pulling the foot brake up by hand and see if it clears the brake light (lamp dims). If so then spray some WD-40 into the pivot point of the foot pedal. I'm assuming the brake light element is OK, sometimes the higher intensity light fails leaving only the running light illuminated.

It's LEDs rather than elements.

The pins inside the light are tiny. I had an issue where power was crossing over via one pin having broken through the plastic housing. A replacement connector solved it.

 

[Taurus]

I second the suggestion of a Maundspeed light. They are beautifully finished and really suit the Bobber. They can sit on the stock light mount