LED tail/brake light and blinker conversion

[Faster Faster]

I am hoping someone may be able to share some knowledge on converting the tail/brake light and turn signals on an Alta to LED's using the stock lighting and tail harness.

Currently where I'm at with this is that if I wire the original incandescent bulb inline (essentially using it as a resistor) with the LED brake light and keep the tail light disconnected then both the incandescent bulb and the LED brake light work when I pull the brake lever but as soon as I try to hook up the tail light I only get one quick flash and then nothing works. If I do the same with the LED tail light and hook it up with the incandescent inline while the brake light is disconnected then both the incandescent and the LED tail light will light up but if I try to connect the brake light they all shutoff. I can also get the LED blinkers to work with the incandescent wired inline.

My two main questions that I can't seem to solve are why the brake light and tail light cause each other to stop working? And secondly how to determine the correct resistor to match the incandescent bulbs output so I can replace the inline incandescent with a resistor?

I saw that NCR mentions a 22 ohm resistor on their blinkers and was curious how to determine if that same size may work with other LED's. I've also read on some other threads where guys have mentioned using a thermistor to control inrush current but all of this is a little bit above my level of electrical understanding.

Any help would be greatly appreciated.

 

[EDR1]

Through my own testing I found the ACM has both a minimum and a maximum expected current load of all lamps.
So all you have to do is find those 2 points and use lamps that have loads within those parameters. I have the original turn signals and brake lamps if you need that data.

 

[HadesOmega]

I just installed the NRC fender eliminator and it uses a resistor to put load on the lights to keep the bike happy. If you deviate a bit the tail light and brake light won't work anymore because I tried to connect the plate light and and it caused the tail light and brake light to not work anymore. I'm sure if I can figure out how much load that light did and downsize the resistor a bit it might work but I just took it off and covered the connector with tape. =/

 

[rayivers]

Try connecting the resistor in series (daisy-chain) with the plate light, then connect the far ends of both to where you connected the plate light before. If you still have problems, you'll need a larger-ohm-value resistor, and if that gets too hot in use you may need a higher wattage rating as well.