Author Topic: Never A Bulb Warning Light  (Read 3790 times)

Offline henbird57

  • Curious
  • Posts: 3
  • 1993 K1100RS
Never A Bulb Warning Light
« on: March 09, 2025, 07:50:02 PM »
1993 K1100RS -I never have noticed a bulb warning light on the speedometer even when my headlight connector was separated from the bulb.  There isn't even the logo in the lower right corner of the speedometer that I have seen on other models(K100).  Previous owner has added after market pulsing brake lights. It has been this way since I bought it in 2012.  Recently the fuse for tail light will blow when immediately starting the bike.  Suspecting he did something with the BMU as I have seen suggested on this site in previous posts.  Is this where I should begin?
  • ELizabethtown, PA
  • 1993 K1100 RS
What did the pop up camper say to the RV?

I go where I'm towed!

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: Never A Bulb Warning Light
« Reply #1 on: March 09, 2025, 09:58:14 PM »
BMU has nothing to do with the headlight. It only monitors the tail and brake light bulbs as well as the brake switches.

Learn more here:
https://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/bmu/bmu.htm

It's not common but it is possible that the insulation from the BMU to the taillight has worn and is grounding to the frame.

First thing I would do is pull the BMU and see if the gray/black wire shorts to ground.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline henbird57

  • Curious
  • Posts: 3
  • 1993 K1100RS
Re: Never A Bulb Warning Light
« Reply #2 on: March 10, 2025, 04:23:17 PM »
Thanks frankenduck, I will let you know how it all worked out.
  • ELizabethtown, PA
  • 1993 K1100 RS
What did the pop up camper say to the RV?

I go where I'm towed!

Offline henbird57

  • Curious
  • Posts: 3
  • 1993 K1100RS
Re: Never A Bulb Warning Light
« Reply #3 on: March 14, 2025, 09:25:17 PM »
Your diagnosis was correct Frankenduck.  Ran another wire to replace, all good now. Thank you.  Collie pup and a collie flower for you!
  • ELizabethtown, PA
  • 1993 K1100 RS
What did the pop up camper say to the RV?

I go where I'm towed!

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: Never A Bulb Warning Light
« Reply #4 on: March 14, 2025, 11:56:17 PM »
Glad that my Internet diagnosis worked for you.

(That Collie-flower poem is a dad joke that I had to endure WAY too many times in my life. Almost daily.)
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Tags: