Author Topic: LED Turn Signals Question  (Read 3595 times)

Offline Jarthur007

  • Curious
  • Posts: 1
LED Turn Signals Question
« on: May 16, 2016, 01:41:39 AM »
Good Evening,
I am rebuilding a 1986 K75 to operational status and I am running into an issue with lighting, specifically with LED turn signals. I could really use your help.

Headlight with turn signals: http://www.uapac.com/antique/headlights/headlight-bulbs/7-34-white-led-crystal-headlight.html
Taillight with turn signals: http://shop.rycamotors.com/tail_light.html

Neither the headlight or taillight comes with wiring instructions so I am running pretty blind, but I have done quite a few tests and read nearly every post in the Lighting section of the Workshop here.

Problem
I have three wires coming from each front (Left/Right) LED turn signal in Red, Green, and Black. I have the bikes wires Blue/Black, Blue/Red, and Brown wires.

With no turn signal wires plugged into the front, when I press a turn button I get a low wailing sound. I am assuming the Green wire from the LED turn signal is ground. Upon plugging in the green turn signal wire to the brown ground wire, the sound pitch stays the same. If I plug in either the red or black led wire to the turn signal wire (L/B or L/R with corresponding turn signal button), the sound goes away, the REAR turn signal starts functioning correctly (blinking normally), and I get an extremely hot wire, smoke, and eventually a blown fuse (5 so far). The front turn signals do no blink correctly during this time.

If I plug in the black (or red, I ran out of fuses to continue doing permutations, will get more tomorrow) LED turn signal cable to the ground wire and another wire to the turn signal wire, I continue to get the low wailing sound, the rear turn signal does not flash, but the FRONT LED lights illuminate.

I feel like I am doing something boneheaded like a ground fault but I can't suss out the issue. If anyone is willing to help I am more than happy to update with pictures, test results, or really anything.
Thanks so much.
-Joe
  • CA
  • 1986 K75

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 2308
Re: LED Turn Signals Question
« Reply #1 on: May 16, 2016, 06:23:22 AM »
Have you modded the flasher module for use with the LEDs yet? Or is your flasher module bone stock?
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline gag1025

  • Ride It Like You Stole It
  • ^ Motobrick Curious
  • Posts: 96
Re: LED Turn Signals Question
« Reply #2 on: May 16, 2016, 07:56:41 AM »
Not sure about your situation but when I replaced the stock 1157 bulbs with LED pop in and twist bulbs (as I call them) on my '53 Chevy Hot Rod Truck I had to also replace the flasher with a double ground flasher. Only then would the LED flashers work.
  • Gibsonville, NC
  • 1992 BMW K 75 RT ABS but soon to be a Naked K75

Offline johnny

  • TrailBrakingThrottleWhacker
  • ^ Quintessential Motobricker
  • Posts: 7652
  • Whacking...n...Chopping Sliding...n...High Siding
Re: LED Turn Signals Question
« Reply #3 on: May 16, 2016, 08:48:05 AM »
 :xeno

there are 2 popular led blinker mods...

1... adding a signalminder...

2... modding the oem...

many threads here about both...

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

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