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Fitting LED resistors

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by mattb, Jun 2, 2012.

  1. G'day All.

    I've bought some LED indicators for my Bullet and some resistors of eBay to fit them, however the resistors are just like the ones in the photo below, such that I cannot work out how one determines which wire connects to which so that the positive going in one side comes out as positive on the other side. Any ideas?

  2. Resistors aren't polar.
    If the connectors are the same on both ends, just plug them in.
    Then retire...
  3. Thanks for that. So the resistors are kind of Buddhist: they don't distinguish between negative and positive, they just see energy and flow with it...

    ...I knew there was something about them I disliked.
  4. yah they suck like that.
    also remember they get effing hot, so avoid stuff like silicone for mounting, it won't last long
  5. Is it possible, then, to ditch the pair of wires coming out and have the two indicator wires go into the one resistor wire? That would be neater.
  6. Personally, I'd just get a non load dependant electronic flasher relay, and forget all the d!cking around with resistors and cutting and chopping looms. But that's just me
  7. Yes, but then you're changing the resistance and therefore the flash rate.
    When the resistor is in series (basically "replacing" one of the indicator wires), you ADD the value of the resistor to the resistance (impedance) of the globe to get the total.
    For resistors in parrallel (ie appearing to go "across" the 2 indicator wires), the total calculation is as follows:

    Now, since Power is a function of voltage and resistance (P=V^2/R), you should be able to calculate the difference in resistance between your old flashers and new ones, and therefore be able to calculate the value of the resistor and where in the circuit it needs to be.

    I hope this helps...
  8. Yep, I messed around with load resistors & got jack of it, $20 for the proper relay. Neater, quicker, easier.

    I tried both series & parallel wiring, at various loads, couldn't get anything to work properly.
  9. I wanted to use a LED flasher can but Honda uses some weird form factor for their flasher can so I couldn't :(
  10. Suzuki (some models) have the relay integrated into the ECU, or some electronic module. All you have to do is make a short section of loom with connecters to suit, tape or cable tie the relay in a convenient location, and Bob's your Uncle.
  11. Hi all,

    So for my GT250, I want to buy a fender eliminator off ebay that probably cost me 45 dollars and come with two LED indicators. And I plan to buy another set so the front and rear are all LED.

    I am aware that you need a resistor in order to make it blink like normal bulb.

    I don't understand how to buy a correct resistor for my indicator. eBay buying guide suggest to buy 50w resistor even though 25w is enough, higher watts can reduce the heat but cost more. My indicator bulbs are RY10W (whats that RY mean?), does it affect which resistor I should buy ?

    Do I pair one resistor for one LED or one resistor for two LED?

    Thanks guys!
  12. The easiest solution is still to replace your flasher can with an electronic one. Simplifies the wiring, no resistors a direct plug in replacement and probably cheaper than two power resistors if you include all the wiring mucking around.

    Re the RY10W designation, Automotive bulbs have a code that describes their type. RY in this case means bayonet fitting, asymmetric pins, amber colour. An RR10W would be red but same package.

  13. For anyone not really following this.
    The resistors are used so that the original flasher can/relay detects enough load to flash at the correct rate. If your bike already has an electronic relay, or indicators controlled via the CPU you may not need to add any resistors at all.
    IMO fitting resistors defeats half the purpose of having LED's fitted. Unless you are just doing it for the looks.
    Some of the benefit of the LED's is to reduce the power being drained when they are being operated. They last 1000's of hours longer than globes, and create much less heat.
    Fitting resistors in line with your new LED just counteracts two of the improvements gained by fitting them.
    You use more power again, and waste energy creating heat.

    If you have fit LED's and the indicators now run fast, the best way to fix it is to fit an electronic or Solid State flasher relay. It's a controlled circuit that will flash at a predetermined rate regardless of the load applied by the indicators. You can buy them to suit most bikes relatively cheaply and they're not tough to fit. You just need to confirm whether you current flasher relay is 3, 4 or 5 wire type, and then buy the appropriate type. Then plug it in, or rewire to suit.

    If you do have to fit resistors then they just get added into the circuit somewhere convenient in series with the new LED's. Somewhere around the flasher unit is good. The resistors with 2 wires on each side (as shown in the earlier pic) have one lead each for the front and back indicators. They don't have a polarity, but must connected so that both front and back indicators match. IE from the flasher can, through the resistor and then on to the indicator.

    If you previously had a 10W globe in each indicator then a 25W resistor for each side should be fine. A 50w resistor will be bigger and so would stay a little cooler if your indicators are on for a long time, but may be harder to fit (or hide) because of their size.

    The other item you may need to check on is your indicator signal lamp on your dash or speedo. If you only have 1 lamp that lights up when you indicate left or right and not separate lamps then you need to check how it is wired.
    Many bikes use a common negative wire from both left and right indicators to operate the signal lamp. If you do have a common negative from this lamp then you'll also need to add a diode to each sides circuit to keep the left and right circuits separate, and not effectively shorted out by this lamp.
  14. wow! really informative! Learned alot!
  15. We aim to please ;)
  16. THANKS´╝ü

    Well, now I've decide to use electronic relay to slow down indicator. Will find out how many wires does my indicator have!