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Discussion Starter #1
Hello all
Im new to this site and was wondering if any of you have done an L.E.D. swap on your turn signals and had no blink afterwords. I tried a search but found nothing. I was told a resistor would do the trick. I was told to get 100k ohm and did but that made for no light at all. Any knowledge or ideas????
 

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I think that resistor should be 100 ohm...not 100k ohm.

However...I think a resistor would make it even more likely not to blink. Typically LEDs don't draw enough current to trigger the "winker relay" as the manuals call them.

JohnnyB
 

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the led's also have very little resistance. usually a 100-200 ohm resistor does it depending on what bulbs you were running before.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs
 

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Fuzzy...you are correct. As diodes no they wouldn't offer much resistance. I spaced and was thinking of them with a resistor already installed.
JohnnyB
 

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Discussion Starter #6
Okay tried 100ohm one on the front and one on the back and it didnt blink. Luckily there only a dollar for five but I will try 200ohms tomorrow.
 

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Rev, typically if they don't blink it's because there is not enough current flowing through the relay....a higher value resistor would typically make that situation worse.

Step one...put the old bulbs back in and see if it blinks (to make sure you didn't damage the relay somehow).

Personally I'd be more inclined to try a 75 ohm resistor...but go too low and you could burn out the LED's.

What kind of setup is this? Is it one of the LED bulbs with an array of several LED's built in? If so...sometimes they have a resistor built in.....if that's the case then you have to install a resistor in parallel with the bulb so it draws more current to trigger the relay.
JohnnyB
 

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first off, what bike? and is the bike running when you test them? are you using LED bulb replacements or are you hardwiring complete circuit boards? If using the replacements are they the standard kind or the kind that blinks and swirls and shit? Did you buy dual stage LED bulbs (blinkers and not running lights)?

If you can't get them to blink with 100 ohm resistor then it sounds like you have an issue with your signals in general and not with the LEDs. LEDs draw very little current and usually the issue is you can't tell the bright from the dim very easily but you should still see a subtle difference.
 

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Discussion Starter #9
This is on a 79 cb650. The blinkers work fine when plugged in I am replacing them with a winker light assembly. This is an array of three lights inside a cat eye blinker assembly. When I removed the rear left blinker and attempted to hook up the new blinker the left side quit blinking(it turns on and stays on). I plugged the old assembly in and viola it worked again. Asked my bike mechanic and he said the L.E.D. doesnt offer any resistance to the blinker pot. Went to radio shack asked the guy behind the counter he told me 100k. Then the light wouldnt turn on at all so I asked on here because I dont have much confidence in the 17 year old at Radio Shack:)
Havent gone either way, been busy this weekend but 100ohm the light would come on and stay on just like without a resistor this leads me to believe that a higher resistor is needed to give resistance to the blinker pot.
Am I thinking correctly on this or am I missing something?
 

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The LEDs need resistance to function, espically on older bikes. I am thinking it might not be such a bad idea to upgrade from a mechanical blinker solenoid to an electric one, and also get an LED resistor setup made for motorcycles.

also have you tried installing the resistor ahead of the solenoid switch? When we converted ym father's bike to LEDs the box he bought plugged in before the solenoid.
 

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I bought a standard 3 pin replacement LED solenoid from china off eBay. just did this in my brother's bike last week. Cost was $12 I think. Worked perfect. Only thing different was his old blinker was round and the new one was square so it didn't fit the mount.
 

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You guys ever hear of ohms law - I * R = V (current * Resistance = voltage) Check your documentation on the led bulb to see what voltage is required to run them. I'm thinking it's 12 volts. The led's should already have a load resistor built into them so you shouldn't have to do anything other than plug them in.
 

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Using reistors for LEDs is counter productive and less than ideal. Resistors turn current into heat and controlling the current is not that accurate for the LED. proper way would be a led driver (doesn't consume much current at all) the uses pulse width modualtion (PWM) to limit the current. This way the LED will work optimally and usually even within broad voltage range. You need "electric" flasher relay as discussed earlier.

I think many commercial ready made plugs already have the circuit built in - either resistors or proper current controlling unit.
 

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quote:Originally posted by bmartin

You guys ever hear of ohms law - I * R = V (current * Resistance = voltage) Check your documentation on the led bulb to see what voltage is required to run them. I'm thinking it's 12 volts. The led's should already have a load resistor built into them so you shouldn't have to do anything other than plug them in.
some do, some don't bob. The old stuff from 10 years ago usually doesn't have a load resistor built in, neither does a lot of the newer chinese stuff (because they want you to buy the flasher unit as well).

Also, a lot of companies don't publish the specs for their LED turn signals on the packaging card, the only way to see the voltage is to open up the signal and read it off the board or the LED itself.
 
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