Author Topic: DIY LED flasher relay  (Read 75037 times)

Offline MEZ

  • Never surrender always busy
  • ^ Proficient Motobricker
  • Posts: 146
  • once dead soon forgotten dream big aim high
Re: DIY LED flasher relay
« Reply #75 on: January 23, 2019, 11:01:28 AM »



One thing I will add here is my own set-up. I have used GS12 switch clusters on my special build which has thrown in it's own unique set of difficulties. Basically the wiring arrangement to the clusters are CANBUS style. One common feed and eight return switched feeds. Because the 'K' wiring system uses switched grounding paths I have had to implement the use of relays to effect the necessary grounding of each function.


One question here is, will the turn signal 'cancel' function still work after the cut..?? Second question, the hazard warning switch, 3 wires, one is ground so the function of the switch is to ground the (Y/V) and (L/W) wires ???









What can I say, (No photo's needed here), I tried the modification shown on this thread for the first time today along with my own mods (see above) with the GS switch gear and it worked straight off, no messing around whatsoever, it just worked..!!! This I can tell you from pure experience doesn't happen very often in the Electrical Jungle it just doesn't

Thank you to whom ever thought this one through and pioneered it... :hail:
  • Angel of the North
  • GS12adv '06, K75 GSadv, CRF500L 'special'

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 10426
Re: DIY LED flasher relay
« Reply #76 on: January 23, 2019, 11:19:40 AM »
What can I say, (No photo's needed here), I tried the modification shown on this thread for the first time today along with my own mods (see above) with the GS switch gear and it worked straight off, no messing around whatsoever, it just worked..!!! . . Thank you to whom ever thought this one through and pioneered it... :hail:
Hello from France too. No need to go to great lengths, just open the existing relay and cut pin 7 to the chip in it. Works fine on mine and I have LED indicators front and back now.
The first person to present this method was bikerboy. Others in thread refined his method down to cutting the trace to pin #7all significant contributions to the LED-craving community.

  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline MEZ

  • Never surrender always busy
  • ^ Proficient Motobricker
  • Posts: 146
  • once dead soon forgotten dream big aim high
Re: DIY LED flasher relay
« Reply #77 on: January 25, 2019, 11:32:39 PM »
Laitch, highlighted by someone on another forum (more than likely an inmate on here too) did you or anyone else reading that has gone to LED all round modify the tail/brake wires going to the 'Bulb Monitoring Unit'..?? 

While I'm on may as well be a cheeky sod and ask, fan override switch anyone...??? I have spliced directly into the switched 12v feed to the fan itself from the relay, back feed from the override switch to relay...?? problematic..??
  • Angel of the North
  • GS12adv '06, K75 GSadv, CRF500L 'special'

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 2299
Re: DIY LED flasher relay
« Reply #78 on: January 26, 2019, 07:32:22 AM »
Laitch, highlighted by someone on another forum (more than likely an inmate on here too) did you or anyone else reading that has gone to LED all round modify the tail/brake wires going to the 'Bulb Monitoring Unit'..?? 
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/bmu/bmu.htm

While I'm on may as well be a cheeky sod and ask, fan override switch anyone...??? I have spliced directly into the switched 12v feed to the fan itself from the relay, back feed from the override switch to relay...?? problematic..??
There are two recommended circuits for adding fan override. One is to bridge the switch across terminals "A2" and "15" on the temperature relay.  The other is to connect one side of the switch to ground and the other side to terminal "E".  One or the other; not both.  If you've done something else (and it sounds like you have), then yes it is problematic.
  • Regards, Robert
Toronto, Ontario

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

Offline MEZ

  • Never surrender always busy
  • ^ Proficient Motobricker
  • Posts: 146
  • once dead soon forgotten dream big aim high
Re: DIY LED flasher relay
« Reply #79 on: February 01, 2019, 12:48:15 AM »

* IMG_3553.jpg (30.7 kB . 522x576 - viewed 998 times)

Hi rbm, just checked here on the '86/'89 75 drawing and as indicated the N/O contact in the temp sensing relay has no electrical connection to the other pins so an override switch straight to this wire will only back feed to an open contact and even when temp is reached and the relay is triggered the closed contact will only double up the feed. Should be fine according to that summary I feel. If the supply was coming from the FI unit then yes I think I would have to reconsider as that would be an issue. My next issue is that I'm going to fit an upgraded fan to the radiator so now to look at current draw.....   
  • Angel of the North
  • GS12adv '06, K75 GSadv, CRF500L 'special'

Offline Bpmdnb

  • Curious
  • Posts: 5
Re: DIY LED flasher relay
« Reply #80 on: February 01, 2019, 11:35:17 AM »
Another green horn here looking to do the mod for the LED indicators,but before I go bastardizing the relay just want to make sure the circuit board in mine will be the same as whats gone before. Also Im going to run an LED strip on the back incorporating the stop/tail light & indicators all in one,will I run into any other issues does anyone know? 1990 k100rs 16v  Thanks in advance 👍
* F5768291-CDD9-41D7-B30A-C5904CCC96C6.jpeg (50.06 kB . 768x576 - viewed 955 times)
  • Ireland
  • K100rs4v

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 2299
Re: DIY LED flasher relay
« Reply #81 on: February 01, 2019, 01:55:15 PM »
No issues.  Here's the sequence of steps:
1. remove the sealant at the base of the module.  It's only a couple mm thick.


2. you'll see tabs capturing and locking the bottom plate to the case.  carefully bend these the tabs out of the way to release the bottom plate


3. remove the bottom plate to reveal the board


4. pull out the board.  This will have SMD parts and not through-hole parts. 
5. Locate U2043.  Identify Pin 1 and then count the pins to locate Pin 7
6. cut the trace on the PCB connecting Pin 7 to the large copper island


For LEDs on the back, see my recent post about the BMU.  I'd love to hear if it works for you.
  • Regards, Robert
Toronto, Ontario

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

Offline Bpmdnb

  • Curious
  • Posts: 5
Re: DIY LED flasher relay
« Reply #82 on: February 01, 2019, 05:24:04 PM »
Top class rbm,will definitely let you know how I get on,might get to the relay tonight & mess around with LEDs tomorrow. Still plenty left on the project to get through......
  • Ireland
  • K100rs4v

Offline Bpmdnb

  • Curious
  • Posts: 5
Re: DIY LED flasher relay
« Reply #83 on: February 01, 2019, 07:24:46 PM »
Fingers crossed for tomorrow
  • Ireland
  • K100rs4v

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 2299
Re: DIY LED flasher relay
« Reply #84 on: February 01, 2019, 07:34:46 PM »
Verify no connectivity between Pin 7 and any exposed terminal pin on that copper island.  Can't tell 100% that the slice is clean through.
  • Regards, Robert
Toronto, Ontario

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

Offline Bpmdnb

  • Curious
  • Posts: 5
Re: DIY LED flasher relay
« Reply #85 on: February 05, 2019, 10:45:37 AM »
Hey Robert,as promised Id get back to you on the relay hack. Worked a treat thanks for the help,very much appreciated 👍
  • Ireland
  • K100rs4v

Offline RetroTexan

  • ^ Motobrick Curious
  • Posts: 57
Re: DIY LED flasher relay
« Reply #86 on: July 21, 2023, 12:10:12 PM »
Just wanted to add a pic of my relay modification that slightly differs from everyone else's.

This is what the relay on my 1989 K100RT looked like and the cut I made. LED lights work great now!

Thanks for this thread, great advice!
  • San Marcos, TX
  • 1990 K100 Custom Scrambler

Tags: