LED turn signal question

Matt Isaacs

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Hey all - I've been messing around with my turn rear signals, trying to convert them to LEDs, on my 80 Special. Trying different flashers. The one I got today from Amazon, recommended from the archive here, has succeeded in getting the left front and rear to blink. But no sign of life front or rear on the right side. I've triple-checked the connections, which all seem good.

Is this a thing, where only one side will flash?

Might i have better luck if I convert the front signals to LEDs as well?

I have another flasher on the way from Superbrightleds, the LF1-S-Flat, But meantime, any suggestions appreciated.
 
Have you checked the connections on both the power side and the grounds on the side that won't flash?
Leo
 
Hmm, not sure exactly what you're suggesting. I've definitely checked the connections at the rear lights. Have not messed at all with the front. Presuming that's fine, but can check. Sorry for my ignorance, but should not sure what you mean by power side and grounds. Are the front and rear linked, i.e. if one is out, neither will flash?
 
You might need to add a diode in the wire to get it to blink with an LED. Also for some reason bikes will only blink when running.
 
You might try a solid-state flasher, as opposed to a mechanical/relay type. I've thought about converting "The Basketcase" to all LED lighting. Since LEDs draw less current than the stock incandescents, what I've heard is that the solid-state units are less sensitive to the difference. Or you can try "loading" the circuits with resistors to simulate a higher draw... :twocents:
 
I had to wire in a diode in the circuit. If you search on this forum there was a thread with a link for the diode. If I recall correctly it was only a few bucks...
 
What I mean by power side is from where the turns get power. The ground side is where the turns ground.
Power flows from the battery through switches and fuses to get to the flasher unit on a brown wire. If one side flashes then this part of the circuit is ok.
Power then flows from the flasher to the turn switch. In the turn switch the power gets sent to the left or right side flashers.
Inside the switch are contacts, often the wires are poorly soldered at the factory and come loose. Check and resolder them.
Now the power flows to the turn signals, through bulbs then out to ground. Grounds are always black wires. If these connections are weak then no ground.
My best guess is you will find te problem in the switch, either poor solder or dirty contacts, maybe both.
Taking the switch apart and cleaning and soldering the joints isn't hard to do but there are many small parts. Work some where where you can catch these small parts. Something like a large cake pan with a white hand towel in the bottom.
Leo
 
With the right flasher you don't need resistors. LED's draw less power, the main reason we use them. Adding resistors restores the greater current draw of stock bulbs.
If your dash has two indicator bulbs, then no diodes are needed. If you have one indicator bulb then diodes are needed.
Leo
 
What I had to do with my recent led turn signals to function correctly was pull the incandescent bulb from the turn signal indicator between the speedo and tach. I assume you already have a led flasher relay installed though.
 
Bushyeyed1, Did you have just one indicator bulb? if so then a pair of diodes hooked in to the indicator circuit will let you use the indicator.
At the indicator bulb socket you have a brown and green wire. trace them back into the headlight bucket. I think they go into a 4 or 6 slot connector. You can remove the wires from the connector and make a short wire that plugs into the connector where the wires were. Or cut them off an inch or so from the connector.
Most any diode will work. I don't recall the ones that are recommended right at the moment but with a search you can find that out. The diode have a line around them closer to one end than the other. This end is the cathode end This end goes toward the bulb. Attach both of these ends to one of the wires to the bulb.
Hook the other end of one diode to the brown wire, the other diode to the green wire. The wire you have left over that goes to the bulb, just ground it.
This way when you use the turns power flows through the diode to the bulb, the other diode stops the power from crossing over and lighting the other side.
I may have the diode direction backwards. It's been awhile since I played with thins like that. A diode is a one way valve for electricity. power can flow one but not the other. Rectifiers use the same ideas to function.
Leo
 
Leo one bulb and I was tracking the addition of a resistor but my indicator is the ticking noise and the front turn signal in the corner of my eye, lol. Might eventually get around to adding one in, but it is doubtful.
 
Leo is exactly right. This is what I had to do. Easy Peasy and just a few bucks.
 
Wait, what? Is this true for all bikes that they'll only blink when running?
No. The alternator provides more current than the battery. A bit of resistance in the old wiring and you need more for the flasher to work.

When you said you checked the grounds, what does that mean? You looked, or used an ohm meter? I recently did work on a 1981 XS1100 that had t same issue. The ground wire on the right rear turn signal was open. Right in the middle. I had to use a meter to find it.
 
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