LED indicator resistors.

[Asher]

Hi guys.
Im in the process of removing the useless mirrors and replacing with bar end mirrors but the indicators are making it awkward.
I have brought some small LED indicators to hide under the screen but when I tested them last night and they flashed too fast.
I will need to wire in some resistors but I'm not sure what to get. A quick google gives heaps of useless results, lots of contradicting info and nothing specifically on the rc390/duke.

So does anyone have any idea on what wattage/ohm resistors work well on these bikes?

Thanks

 

[jokerio]

I believe all you need to do is replace the stock flasher unit with an electronic flasher unit. The stock unit are not compatible with LED's.

 

[RC390 Fan]

You need some resistors wired in parallel with the new LED signals. Amazon.com: 4Pcs Aaron 50W 6ohm Load Resistors - Fix LED Bulb Fast Hyper Flash Turn Signal Blink Error Code: Automotive

 

[Fasteddy]

If it is a New Zealand spec bike it should already have the correct three wire flasher, You could measure the resistance of the inline resistor pack in your rear LED signals....
The mirror unit has the current limit resistor built into the module.

 

[Fasteddy]

FWIW,

I have a complete LED system I plan to install this winter from an Australian bike, the resistor pack in the rear LED signals is 27 ohms in series and consists of chip style resistors dissipating less then a watt, from a 12 volt battery it draws 80mA. the mirror mounted unit with internal series current limiting to protect the much brighter LED draws 280mA. 6 ohms at 12 volts would be over 2 amps so I doubt the solid state three wire flasher unit (black with blue connector) would survive very long as it is intended for a low current LED system of less then .4 amps.

You likely need to add about 27 ohms @ a couple watts in series with your after market turn signals. And my measurements match calculations....

 

[Asher]

Thanks.
The only part im now confused about is how the wattage relates to the resistor. Is the wattage related to the rating of the resistor, as in choosing a too low wattage resistor may cause it to burn out? Or is there more to it?

 

[Fasteddy]

Thanks.
The only part im now confused about is how the wattage relates to the resistor. Is the wattage related to the rating of the resistor, as in choosing a too low wattage resistor may cause it to burn out? Or is there more to it?

"too low wattage resistor may cause it to burn out" is correct!

The load resistors referenced that would be put in parallel are meant to draw 2 amps and emulate a pair of 1156 / 1157 standard bulbs, LEDs are a semi conductor device and need a current limiting resistor in series.

The calculated dissipation in watts for the resistor you need is 5.6 watts, but, in reality it is much lower because of the duty cycle from flashing off / on, this is why the rear is getting by with way smaller (power wise / physical size) 6 resistors on the little strip circuit board in line.

The US spec SuperDuke R uses the same turn signals both front and back as the back ones on your bike and I have been looking at modifying my standard SuperDuke to the same setup... Hope this helps, feel free to PM me if you need more, and yes there are folks here in the US that would have interest in your old mirrors or just the LED inserts BTW...

 

[Treachery]

I understand that the resistors fix the problem. I don't understand going to that trouble when replacing the flasher fixes it without the other trouble. Plug & play.

 

[Fasteddy]

I understand that the resistors fix the problem. I don't understand going to that trouble when replacing the flasher fixes it without the other trouble. Plug & play.

Resistors in parallel or series, big difference between the two systems.

No, not plug and play, Non North American version has a 3 wire low current solid state flasher unit made for all LED signals. Our North American bikes have a two wire flasher unit made for the higher current incandescent bulbs. And the plugs are not 1/4" blade style.

Oddly the service manual shows only the non North American system.

 

[Treachery]

I didn't see that he was in NZ.

But, electricity is electricity. The size of the terminals doesn't matter either, if you don't mind making some modifications; either way, it should be easier than wiring in and hiding the resistors. I used the Tridon EP35 on a three-wire system. I found This unit on Amazon, and I bet that if you search for "two terminal LED flasher" you can find more, and if you've got a smart parts guy at your local NAPA, they can find one for you. Doesn't help Asher, but that's what I'll do if I ever swap out.

 

[jokerio]

Euro-spec turn signals (Indicators)
http://www.rc390-forum.com/forum/ap...euro-spec-indicators-front-rear-blinkers.html

 

[Asher]

It's not really a big deal to wire in resistors as I will have to wire in the new indicators anyway.
i brought some 5W 27ohm wire wound resistors yesterday and wired them into the new indicators. I will have a go at installing them tonight.
With the solid state flasher on my NZ spec bike the new indicators don't flash super fast, just enough to bother me.

 

[Asher]

So i tried the resistors and they didnt seem to make any difference to the flash rate, i even went up to 100ohms and it made no noticeable difference so i have given up.
Im just going to have to deal with the indicator flashing faster.

 

[JKBC]

Well this had me worried since I just got genuine KTM RC 390 LED blinkers from Germany a few days ago. Well easy enough to plug it in to see how fast it blinks and it's fine as far as I'm concerned as you can see in this short video I just shot.
https://vimeo.com/137691419 ...and these bolt into the stock mirrors.

 

[CortEnis]

I also have a complete LED system and also i am plan to install this winter from an Australian bike, the resistor pack in the rear LED signals is 27 ohms in series and consists of chip style resistors dissipating less then a watt, from a 12 volt battery it draws 80mA.
The mirror mounted unit with internal series current limiting to protect the much brighter LED draws 280mA. 6 ohms at 12 volts would be over 2 amps
You likely need to add about 27 ohms a couple watts in series with your after market turn signals.