Author Topic: LED signals... Please confirm what I think I already know  (Read 88 times)

Offline brucedavidculver

  • Trade Count: (+1)
  • AMA Supersport Racer
  • **
  • Posts: 134
  • Karma: +13/-0
LED signals... Please confirm what I think I already know
« on: May 22, 2020, 10:13:11 PM »
I feel like I shouldn’t have to ask this question as I seem to deal with it every time I fiddle with a bike but it seems like each scenario is different... Single LED indicator with incandescent signals, dual incandescent indicators with LED signals.... etc... 

Replaced the stock turn signals on the GS with LEDs... now all four signals flash when I turn either side signal on.... which I expected.  Taking the incandescent indicator bulb out solves the problem which means that the signal is just backfeeding through the loop (Right?).  So, installing a zener diode  on the positive side of the circuit, facing the correct direction, should solve this problem. In other words, I should be able to solve this with one diode at the indicator bulb... or could I solve this with a LED indicator bulb as well, as that should also prevent backfeeding? Just thought I would confirm this with somebody before I go to cutting wires. LOL.
2006 GS500F (latest project and probable "scrambler-type-thing")
2005 GS500F (“café-ish"mod)
2017 Benelli TNT600 SOLD
2004 GS500F (scrambler mod) SOLD
2009 GS500F (street fighter mod) SOLD
1982 GS450 (café racer mod) SOLD

Offline The Buddha

  • The guru Ba-moo-derator
  • Administrator
  • Trade Count: (+52)
  • Motorcycle God!
  • *****
  • Posts: 26306
  • Karma: +115/-0
Re: LED signals... Please confirm what I think I already know
« Reply #1 on: May 22, 2020, 10:19:47 PM »
We install a wagner 552 electronic flasher relay - however the situation we usually have is that the T/S'es on 1 side don't flash - they are solid usually. Not all 4 flashing - maybe the relay in yours is different than the 89-00 one.

Cool.
Buddha.
-----------------------------------------------------------------
I run a business based on other people's junk.
-----------------------------------------------------------------

Offline brucedavidculver

  • Trade Count: (+1)
  • AMA Supersport Racer
  • **
  • Posts: 134
  • Karma: +13/-0
Re: LED signals... Please confirm what I think I already know
« Reply #2 on: May 22, 2020, 10:29:09 PM »
We install a wagner 552 electronic flasher relay - however the situation we usually have is that the T/S'es on 1 side don't flash - they are solid usually. Not all 4 flashing - maybe the relay in yours is different than the 89-00 one.

Cool.
Buddha.

Yep, I already installed the electronic flasher. I know the LEDs don't draw enough current to operate the old-school analog relays. The fact that removing the bulb solves the problem indicates that it is something in that part of the circuit that is causing it. I really feel like I should not be puzzled by this. LOL. Just want to be 100% certain before I start cutting things.  Looks like I may make some temporary cheesy little bypass to stick a diode in there and see if it fixes the issue.
2006 GS500F (latest project and probable "scrambler-type-thing")
2005 GS500F (“café-ish"mod)
2017 Benelli TNT600 SOLD
2004 GS500F (scrambler mod) SOLD
2009 GS500F (street fighter mod) SOLD
1982 GS450 (café racer mod) SOLD

Offline Bluesmudge

  • Trade Count: (+4)
  • MotoGP Racer
  • ******
  • Posts: 2039
  • Karma: +36/-0
Re: LED signals... Please confirm what I think I already know
« Reply #3 on: May 22, 2020, 10:42:45 PM »
Ok, I will confirm what you already know (I have successfully solved the problem on my bike and sort of understand how I solved it).

To solve the 4 way flash problem, you need a diode before the turn signal dash indicator for each side of the turn signal circuit and also re-wire so that the circuit grounds to the common ground instead of back through the bulbs. The stock wiring that is grounding through the other side of the turn signal circuit isn't enough to light up an incandescent bulb but it will light up an LED. Here is a before and after wiring diagram I quickly found through a google search.



This will work with LED or incandescent bulb in the dash.
Superbrightleds sells a "kit" to do this for a very reasonable $2.29 that saves you the trouble of having to know how any of this stuff actually works.
https://www.superbrightleds.com/moreinfo/flashers-load-resistors/metric-bike-diode-kit/1190/2805/
That kit is what I used and it worked perfectly.

You already solved the other LED problem (quick flashing) with an electronic flasher.
« Last Edit: May 22, 2020, 10:52:36 PM by Bluesmudge »

Offline brucedavidculver

  • Trade Count: (+1)
  • AMA Supersport Racer
  • **
  • Posts: 134
  • Karma: +13/-0
Re: LED signals... Please confirm what I think I already know
« Reply #4 on: May 22, 2020, 11:19:13 PM »
Ok, I will confirm what you already know (I have successfully solved the problem on my bike and sort of understand how I solved it).

To solve the 4 way flash problem, you need a diode before the turn signal dash indicator for each side of the turn signal circuit and also re-wire so that the circuit grounds to the common ground instead of back through the bulbs. The stock wiring that is grounding through the other side of the turn signal circuit isn't enough to light up an incandescent bulb but it will light up an LED.

F-a-a-a-a-a-ntastic!  Once again my "online motorcycle friends" (my wife's nickname for the forum) come to the rescue.  On an unrelated note, I keep telling myself that's just a cute pet name and not a subtle slur...lol.  :roll:

Anyway, as I already have the diodes from previous builds I won't even need the kit.  I just wanted some confirmation as to where they went.

Thank you sir!

B.
« Last Edit: May 22, 2020, 11:26:38 PM by brucedavidculver »
2006 GS500F (latest project and probable "scrambler-type-thing")
2005 GS500F (“café-ish"mod)
2017 Benelli TNT600 SOLD
2004 GS500F (scrambler mod) SOLD
2009 GS500F (street fighter mod) SOLD
1982 GS450 (café racer mod) SOLD

Offline SK Racing

  • Trade Count: (0)
  • AMA Supersport Racer
  • **
  • Posts: 64
  • Karma: +3/-0
Re: LED signals... Please confirm what I think I already know
« Reply #5 on: May 23, 2020, 05:57:38 AM »
Make sure that you use the correct type of diode. A zener diode is a voltage regulator and that is not what you need in this case.

A "normal" silicon or germanium diode has a voltage drop between 0.6 to 1.7 volts. Rather use a Schottky diode where the voltage drop normally ranges between 0.15 and 0.45volts.

 :thumb:


You don’t stop riding when you get old, you get old when you stop riding!
1939 Panther 600cc Single - Stolen, 1970 Suzuki 50cc - Sold
1969 Triumph Bonneville 650 T120R - Sold, 1981 Honda 750F - Sold
1989 Suzuki GS500E - Sold, 2004 Suzuki GS500F - Current ride

Offline The Buddha

  • The guru Ba-moo-derator
  • Administrator
  • Trade Count: (+52)
  • Motorcycle God!
  • *****
  • Posts: 26306
  • Karma: +115/-0
Re: LED signals... Please confirm what I think I already know
« Reply #6 on: May 23, 2020, 06:08:54 AM »
There were those Schottky diode based regulator/rectifiers with mosfets in them, damn good those were.
BTW I've not seen why a diode would be needed to a T/S cos an electronic flasher has a clock and this and that and LED's are diodes - they can be used in the same sense you would say use 4 of em in a rectifier bridge - I have seen it done, but I can see how a current limiting resistor may be useful. Let me look at the circuit again.

Cool.
Buddha.
-----------------------------------------------------------------
I run a business based on other people's junk.
-----------------------------------------------------------------

Offline mr72

  • Trade Count: (0)
  • MotoGP Racer
  • ******
  • Posts: 2375
  • Karma: +39/-0
  • Musician, Engineer, Sci-Fi Author
    • Josh's Books
Re: LED signals... Please confirm what I think I already know
« Reply #7 on: May 23, 2020, 12:28:32 PM »
a schottky isn't necessary. A normal 1n4001 will work fine or basically any ordinarily diodes. While you're at it you can now use a led dash indicator too.

Like SK said, not a zener.

Offline brucedavidculver

  • Trade Count: (+1)
  • AMA Supersport Racer
  • **
  • Posts: 134
  • Karma: +13/-0
Re: LED signals... Please confirm what I think I already know
« Reply #8 on: May 23, 2020, 08:36:31 PM »
Thanks everyone. Good info all around.  I'm not sure why I thought it was a Zener... I just remembered that name (maybe I just liked it... lol).  Whatever I used last time worked and I still have some, so I'll use what I have.  I'll probably grab LEDs for the gauges.  As long as I am fiddling around up there, might as well upgrade.  :thumb: 
2006 GS500F (latest project and probable "scrambler-type-thing")
2005 GS500F (“café-ish"mod)
2017 Benelli TNT600 SOLD
2004 GS500F (scrambler mod) SOLD
2009 GS500F (street fighter mod) SOLD
1982 GS450 (café racer mod) SOLD