I learned on this forum that many of you have installed the Signal Dynamics Corp (SDC) brake light modulator. See the link here from Drag Specialties.

http://www.dragspecialties.com/fatbook/17/342/5922112?q=brake%20back%20off

I contacted SDC directly becauseI was uncertain if the modulator would contol only the brake light on my rear fender or if it can also control the brake lights on the Tour-Pak on my 08 Ultra. They said the unit can handle both sets of brake lights (the fender and the Tour-Pak). I was hoping for this answer.
[*]Is this true for those of you who have installed the SDC unit?[/ul]HOWEVER, the SDC rep said they have heard thatthe device may interfere with the Harley-Davidson cruise control for some people.
[ul][*]Do any of you with the SDC unit experience problems with your cruise control?[*]Could there be a difference based on the model year of the bike or if the cruise control was an add-on?[*]Is there another brake light modulator you would recommend that you know does not interfere with the cruise control?[/ul]
Thanks in advance.

Brad

 

Mine has been on for 4 years. No impact on the cruise.

 

Can't answer your most important questions, but obviously the throttle on the '08 Touring bikes is electronic; prior years the throttle was mechanically controlled by cables--so the cruise control is different for the electroinically controlled cruise compared to the mechanical/cable controlled cruise units.

 

I've had one on all of my previous bikes but haven't put one on my 08 UC yet partly because of this question. If you wire it in under the seat it will definitely control all your lights, you might want to be careful though if you also pull a trailer and have the trailer wiring harness as adding a trailer to it too might overload the module. On previous bikes I always wired the trailer harness in before the modulator to make sure I wouldn't burn it out. I'm still looking for a good solution, part of the problem is that the lights on the tourpak aren't turn signals (I sure wish they were)....I would like them to work as turn signals too before I put a modulator in.....so far I haven't found a good/easy way to make that change.

 

As a follow-up to my original post above, I contacted SDC again and asked if the cruise control issue is only related to the new electronic throttle on 2008 models. They said they do not yet have any customer feedback associated with 2008 models; their experience is with pre-2008 models. They said that with the SDC unit installed, the cruise control logic thinks the brake light bulb is inoperative and it will therefore not engage the cruise control.

I'm still interested with HDF member feedback. If you have the SDC unit and you have and use cruise control without a problem, I will probably install the unit and hope for the best.

Thanks again.

 

I installed it to only operate the Tour Pac lights. I still wanted to have a steady burning brake light at all times. Now the Tour Pac will flash...hopefully getting attention...and the light on the fender will be steady "on". No problem at all with cruise control.

 

Thanks for the responses. The SDC brake light modulatoris now installed. It works fine and does not impact the cruise control as thought to occur by the SDC rep. I'm guessing that someone installed it incorrectly and this caused them problems.

 

2008 EG CLASSIC...NO PROBLEM WITH CRUISE AND ONLY MODULATES THE REAR BRAKE LIGHTS. I HAVE THE KIT THAT CHANGES MY REAR TURN SIGNALS TO BRAKES LIGHTS, THE TOUR PAC SPOILER W/ LIGHTS,AND ALSO THE TRI-BAR RUN/BRAKE LIGHTS INSTALLED AND NO AFFECT ON ANY OF THOSE...RIDE SAFE