No announcement yet.

LED "Retrofit" Failure... Looking for Suggestions

  • Filter
  • Time
  • Show
Clear All
new posts

  • LED "Retrofit" Failure... Looking for Suggestions

    Hey guys, it's been a while since I've logged into here... and a long time since I've worked with LED's. Hopefully someone can help me figure this out.

    Here's the project:

    The bike is a 2019 Honda CRF450L (dual sport dirt bike). It comes from the factory with full LED lighting, but I wanted the rear end to be more sleek so I've swapped the rear from that of a CRF450X. The 450X doesn't come with turn signals, so I've purchased some flush mount LED turn signal lights and swapped out the PCB with my own array (to make it brighter). The array consists of two parallel strings of 4 Osram Power TopLED's in series. I using a 10V linear regulator with resistors to power the strings at ~50 mA each.

    The 450L's stock turn signals use a single high power amber LED with a series resistor from what I can tell. I haven't torn it apart to check myself, but I've powered it on the bench and at roughly 7V the LED lights up dimly. The current increases as the voltage increases, so at 12V the LED is drawing 200 mA or 2.5 W. My LED array is drawing 108 mA at 12 V or 1.3 W.

    My turn signals work perfectly on the bench, but when I plug them into the bike, they don't light up at all. The front turn signals hyper-flash extremely dimly when I have my rear turn signals connected to the bike. If I unplug my rear turn signals, the front turn signals hyper-flash, but are not dim. They're bright like they should be.

    I've tried connecting a 100 ohm resistor in parallel with the array to see if matching the OEM load would fix the problem, but it seems to have no effect.

    Has anyone seen this type of problem before, or have a suggestion on what to try next?

  • #2
    Yes I am aware of the problems swapping turn signals on the newer Hondas. But I wanted to change front and back turn signals.I bought special adapters (made by Kellermann or Rizoma) for the aftermarket turn signals and didn't have to do anything else with the wiring.

    The problem occured due to the front LEDs beeing dimmed as running lights and getting full brightniss with the blinker.

    The topic is in German but you should be able to read it via google translate. Good Luck.
    Subaru Outback retrofit:
    License plate lights with dual brightness: