So my bike is new and today I noticed that only the left running light in the rear was working. Is this right? I know that the running-signal-brake lights are all combined on the nightster, but never noticed the right light out. Brake and signal both work, but no running on the right. I am beating a dead horse. So the question is no running rear right light, fair or foul? If foul, whats the issue?

 

Both lights on the rear of a Nightster, Iron, and 48 are running lights. You probably just burned up one of the filaments in the bulb. Swap in a new bulb and you should be good to go.

 

As Chevy stated, you blew a bulb filament. Replace the bulb.

 

Unless you have the LED sealed unit,
then you have to just live with it (Like i do)
or replace the whole unit...and over here they sell them as a pair.
But your bike is brand new so the dealer must sort it out.