Motorcycle Repair: rear brake light

Question
The rear brake light on my 1979 Harley Davidson Low Rider is not coming on. Front brake makes light come on fine. I changed the bulb just to be sure. Rear brakes work fine, just not getting brake light to come on. Any suggestions?

Thanks for your time Mike.

Answer
You have a brake light switch in the line going to the brake. It will have 2 wires going to it. When the switch is on one of the wires should have 12 volts and when you press the brake pedal the other one will be hot. If there is no power on either one then you have a short and will have to trace the wire. If you have power at one wire, but not the other, when you press the brake then the switch is bad and needs replaced.
Good luck and happy riding
Mike