I'm changing out my rear turn signals to brake lights and turn signals. I have the kit from Harley with the red lens covers. Do I need to use a different bulb like a dual filliment bulb? Or can I use the 1157 or 1156 single filliment? Just wondering what bulb I should be using with this kit? Bike is a 2007 1200c

 

In the absence of replies....here is my input based on my experience. Not sure what is included in your kit, but normally dual purpose lights need dual filament bulbs. I did read somewhere that you can use a single element bulb but the kit needs to modify the current so the light can change intensity. I have a single element LED on my saddlebags and tried to use them for dual purpose - running and brake. Installed a converter harness but it did not work...the wires got extremely hot so rewired and use them as additional brake lights.

 

I have the kit and use the same bulbs as before. No change to bulbs.
Sammi

 

Before I went LED, had that set up from HD. Used same bulb, worked great

 

I have the same year & kit & the HD kit worked perfectly and uses the stock bulbs.
I already had the smoked lenses so I wanted to use red bulbs, I tried red LED bulbs but they wouldn't flash properly so I got red incandescent bulbs from Kuryakyn.
I also wasn't quite happy with how obvious as brake lights they were to distracted cages behind me so I kept the brake wire (bypassed the converter box) and installed a LED brake light bar up by the licence plate. If I did it again I'd get the fender lip LED brake light they have now I think on the Nightster, they didn't have them when I did my conversion.

 

maybe read the instructions in the kit ... just sayin' ...
seriously, though ... the 'box' that plugs into the lighting harness uses your existing single filament bulbs but just regulates the power to them so that they ACT like dual-filament lights. This device is usually referred to as a "Run-Brake-Turn" module.
You can't put dual filament bulbs in your light housings without gutting them and replacing the sockets with dual filament sockets or buying new bullet lights that are pre-wired for dual filament bulbs (like the ones on a Nightster) ...

 

Instructions say nothing about changing bulbs. I put the 1156 bulbs that are single filament and it does work as it should.