[Blindstitch]

Well first you realize that it is meant to stay on low at all times. And then when you step on the brake lever or hand brake it is meant to glow bright.



Does it get brighter when you grip the hand brake? The wiring there is pretty simple. I would suggest that you inspect it. Foot brake switches can seize due to rust and other things in the switch.

 

[Blindstitch]

I wouldn't be surprised if the little rod in the switch is getting stuck when pulled and doesn't want to go back right. Follow the wires back from it and unplug it on one side and see what happens when you pull the front brake lever. If it acts normal then it's most likely the foot brake getting stuck. They sell these foot brake switches on ebay for $5 or so.