Topic: 73 CB500 Turn signal issue

[grhollander]

Running LED turn signals in the rear. Using two prong flasher and they work fine. When I put the bulb in the idiot light socket, it causes both rear signals to flash regardless of switch position. Also the idiot light doesn't work when the lights are flashing.

[markmyodb]

it's due to the handlebar indicator lamp.  It becomes a source  "ground" due to the very low resistance of the LED bulbs.

You will need to add resistors to the circuit. I tried 1 watt, 10 OHM, then gave up, put the incandescents back in.

I use a LED headlight to reduce the low RPM load on the Battery.

[CycleRanger]

You might also try using a solid-state flasher if you're still using a mechanical one.
I switched over most of my bulbs to LED but had to use a solid-state flasher.

[grhollander]

I'm using solid state. I'm going to see if I can track down an LED light that will fit in the idiot cluster

[Kenzo1979]

LED signal bulbs, LED idiot light - w/ diodes in the bucket connection to the signals, LED flasher unit.  Should work perfectly.


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[Deltarider]

Or simply return to bulbs. No hasle, cheaper and better noticed blinkers and brakelights.

[dave500]

im with Delta,most LEDs ive seen look pretty washed out in sunlight and hardly bright enough at all.

[Deltarider]

It's mostly the glow on and off effect that Leds lack. Leds switch on in a nanosecond, bulbs flame up, so to speak and somehow we humans tend to be more alarmed by this. At least that goes for me - I almost rear ended a bus with its Led brakelights on, simply because I had missed the process they got on. But nowadays, with leds and old bulbs equally around in traffic... anyone can find it out for him self. Blinkers with old bulbs are also better noticed from an angle, leds hardly at all.

[Kenzo1979]

Yeah, nothing against incandescent.  But if the poster wants to use LED, here’s the thing that makes them look good and not washed out:

- Match the color to the lens:  Amber for blinkers, Green for neutral, Blue for Hi beam, Red for oil pressure and brake lights.  Trust me it makes all the difference.

- and probably the most important thing that is repeated on this forum regarding just about everything:  Don’t use inferior products.  There are cheap Amazon 20pc for $9.99 LED’s and then there are good ones.  I bought most of mine from SuperBrightLEDs and that had to be  10 years ago or more and everything is still working just as bright as the day I bought them.  And my stuff is definitely way brighter and more visible than the incandescents that were originally in there. If you want I can post you model numbers of what I purchased in the past.


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[Kenzo1979]

The white Ba9’s were for the gauge illumination.  Not sure why I bought two different types, maybe just testing different types.  Pretty sure I used the one with 4 Qty.

Note:  you need dual filament for tail/brake and if you’re doing running lights on the signals.  500 doesn’t have stock running light connections, but the 550’s do.  This order was for my 550.

Good luck


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[Kenzo1979]

And this is how you keep all of your turn signals from blinking at once when you use your turn signal switch. In the original wiring, when you turn on one side of the turn signal switch, the other side is grounded. With an incandescent bulb it doesn’t matter which side the voltage is applied so it lights in either direction. With the LED, it doesn’t work that way, so you have to permanently ground one side and feed the other side with both signal inputs. But when you do that, voltage is applied to both sides at once so they all light up together. That’s where the diode comes in. Diodes are a one-way current flow device. So it will block any power from feeding back to the turn signals that are not supposed to be on. 


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[Little_Phil]

In the original wiring, when you turn on one side of the turn signal switch, the other side is grounded.

Yes, this is done to light the idiot light and in the original system the current through to idiot light flows in different directions depending on what side is selected.

[Kenzo1979]

Just another thing I thought I would add in case it applies anyone else reading this…but it doesn’t apply to the 500…

If your bike came equipped with a turn signal buzzer, I have found that instead of using diodes for LED turn signals/idiot light junction, you can scrap that buzzer and connect your brown/blue LH control wire to orange on the dash light harness and light blue on the dash harness to any ground - I don’t remember the gender of the connectors, so it may be necessary to change them or make some adapters.  But this also makes the turn signals and dash light work without the use of diodes and without interference from one another.


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[grhollander]

And this is how you keep all of your turn signals from blinking at once when you use your turn signal switch. In the original wiring, when you turn on one side of the turn signal switch, the other side is grounded. With an incandescent bulb it doesn’t matter which side the voltage is applied so it lights in either direction. With the LED, it doesn’t work that way, so you have to permanently ground one side and feed the other side with both signal inputs. But when you do that, voltage is applied to both sides at once so they all light up together. That’s where the diode comes in. Diodes are a one-way current flow device. So it will block any power from feeding back to the turn signals that are not supposed to be on. 

I was messing around with my wires and now the rear LED blinkers are flashing correctly, even with the incandescent idiot bulb in place. I'm using aftermarket controls and for the turn signals, the switch only has blue, orange and grey wires. Does the ground come into play with the OEM controls?

[Kenzo1979]

Off the top of my head, I’m going to say no.  It’s the turn signals themselves that are grounded.  Even the turn signal relay only uses black and gray, green (ground)  goes unused.

And for the record, I don’t really think it matters if the indicator bulb is incandescent or LED.  But if your turn signal bulbs are all LED, you will usually need that diode modification at the junction of the indicator bulb for Left and Right to work independently.  It’s that connection at the indicator bulb that usually causes the issue.


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