LED indicator resistor

  • Thread starter Thread starter Ish
  • Start date Start date
I purchased a resistor kit from Ebay which when I checked it was 10w & 8 ohm but these didn't work. It was listed as a universal kit for LED motorcycle indicators.

I measured the resistance of the standard indicator and it was 3 ohm so I then tried a 10w 3 ohm resistor. This flashed the indicator and at the correct speed but the resistor got too hot.

I'll get a higher wattage 3 ohm resistor.
 
something like 6ohm 25 watt in parallel would suffice. i used these myself and they worked alright.

there are 'prewired' ones on ebay, but they cost way too much imo. if you're any good with a soldering iron they can be picked up for around £1 each and are real easy to add in.
 
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Yep. Stay away from resisters. They generate so much heat they could damage your fairings. A flasher relay will cost a bit more but will fix the whole bike for LEDs and be much neater.
 
The resistors are a bit of a bodge so I will get LED for front and then a relay as well.
 
Ish said:
I measured the resistance of the standard indicator and it was 3 ohm so I then tried a 10w 3 ohm resistor. This flashed the indicator and at the correct speed but the resistor got too hot.

I'll get a higher wattage 3 ohm resistor.
Click to expand...

The cold resistance of the lamp is not relevant, the resistance of the filament increases greatly at it's working temperature. An automotive lamp on a 12v system is rated to gives it's marked output power at 13.5v.

13.5^2/21 = 8.6 Ohms. This is per lamp i.e you'd need an 8 ohm resistor per LED lamp, four in total if replacing front and rear indicators. A vastly better solution is to get a solid state flasher relay that gives the correct flash rate with LED lamps.
 
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