LED Turn Signal Question

[jeffedmo]

I've searched and searched for a solution to this issue but just can't quite determine what the actual solution should be. There's a number of similar posts but I haven't seen my exact issue and resolution. So I thought I would try posting this to see if I can get a specific answer...

I have a 1981 GS850. I replaced all four turn signals with LED lights. From the posts that I've seen, it seems that when most people do this they get a fast-flash situation. But I don't. When I engage my turn signal switch (doesn't matter if it's right side or left), all four lights light up and stay on solid. Again, no blink and all four lights illuminate.

As per many post suggestions, and even one guy's detailed tutorial, I've purchased an electronic flasher and tried wiring it in. Does not fix the problem. With the new flasher in place they all still lit up but they were much dimmer.

I'm fine with installing wired-in load balancers but I'm hesitant because I haven't seen anyone with the same problem as me. And I've seen differing answers in regards to what ohm & watt resistors I would need to fix this issue.

Any ideas?
Thanks!

[DanTheMan]

First off, welcome to the GSR forums! The problem with using LED lights for flashers is the fact that there is not enough resistance to make the flasher unit work. If you were to use them in addition to the regular lights, they would all flash. Also, you should make sure all your wire connections are, the grounds are good and that you're working with a fully charged battery. When I'm testing electrical stuff on my bike I plug in the battery tender to keep my battery up. If your battery is less than 12.3 volts, it won't power the flasher system adequately.

[Macguyver]

LED Flashers

I have replaced most of the lighting on my 650 with LED, and ran into a similar problem.
For me a simple trip to the auto parts store did the trick.
I picked up a two post electronic flasher module and it plugged right in to the stock plug.

Make sure the electronic flasher is not the heavy truck version, since it will not work with small LED setups, those do still need a certain draw to operate.

I believe the one I purchased was an ?EL-12? Electronic Flasher Module. These will flash no matter what, you you should be able to plug it in, turn the signals on, and you should be able to hear the solenoid clicking even without any lights hooked up to it. They are based on a small timing circuit which is load independant, so they don't need current draw to heat up a bi-metallic switch to cause the flashing.

If in doubt, you can try putting the old incandescent bulbs back in for the front signals and try it again, I bet this will cause it to flash because of the extra current draw. If that is not an option, you can wire in an in-line resistor of approxiamately 100 Ohms to start, and work your way up to a max of around 1000 Ohms(1k Ohms). Any more after that and the extra current draw will make switching to LED's a moot point, other than cosmetic reasons that is.

Hope this helps,

[jeffedmo]

My flasher is a 3-prong. You had a similar problem or the same? Did all four lights come on no matter which side you switched on? I'm pretty sure my bike has the auto-cancelling system in place (the turn signals had been removed by the PO so I haven't been able to test this). Which, as I understand it will no longer function if I just replace the flasher relay. I don't mind this, however, as per other instructions I tried one of these and it didn't work.

[jeffedmo]

So now I'm trying to determine what size resistors I will need. The bulbs that came out of the original turn signal lamps are 12v 23watt bulbs. How do I determine what resistor I need to simulate the load that these bulbs create?

[Macguyver]

LED Resistor calculator

Here is one of the handiest link in my favorites.

http://ledz.com/?p=zz.led.resistor.calculator

This will let you calculate the proper resistor based on all sorts of set-ups, series,parallel, single, multiple LED's.

You do need to know a few things first though, supply voltage(I usually just put in 13v), voltage drop across LED(depends on the color), desired current(depends on rating on LED, most handle 20-50mA)

However, if you are using prebuilt LED lights with multiple LED's in them, they will already have a resistor built into them so they can handle the ~12-13v supply voltage. With these, I would start with a 1k Ohm resistor in series with each light and go from there. Make sure to hook them all up the same, at the same time, then test. Since we are looking to get things balanced and tested in real-life conditions similar to the final running condition.

If you are in no great rush to get this going and you do not have resistors readily available, I can send you some for you to experiment with, just let me know how many lights you are using and I can send you an assortment.

Hope this helps,

[Steve]

How do I determine what resistor I need to simulate the load that these bulbs create?

Actually, that's rather easy.

Just go to Auto Zone and get the pack that has two resistors in it that are designed for it. Costs about $12.

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