Author Topic: Handle bar switch assembly  (Read 318 times)

Offline stryder

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Handle bar switch assembly
« on: September 14, 2019, 12:44:12 PM »
1987 K75, but has K1100rs handle bars.

LH switch assembly.  I think it's the same assembly: hi-beam, pass flasher, horn, and turn signal switches.

*Low beam not working*, high beam works, pass flasher not working. Disassembled, cleaned up, no crude no damage.

Disconnected the switch at the plug under the tank, and no crud. 

Reassembled everything, no joy.

I think I need a new switch assembly.

Does anybody know of a good source other than e-bay?

Local BMW shop tells me that switch was discontinued.

Thanks.
Southern Ontario, Canada.

Offline Soggz

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Re: Handle bar switch assembly
« Reply #1 on: September 14, 2019, 01:20:26 PM »
BMW motoworks or Motobins have good second hand units. They R in England.


Just sayin’
  • Down in Selwood Forest
  • 1986 K75C, 1982 Honda CX500EC Eurostreetbrat
One More Of These,One Less Of Those...

Offline stryder

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Re: Handle bar switch assembly
« Reply #2 on: September 14, 2019, 01:29:17 PM »
Southern Ontario, Canada.

Offline Laitch

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Re: Handle bar switch assembly
« Reply #3 on: September 14, 2019, 01:55:41 PM »
1987 K75, but has K1100rs handle bars.

LH switch assembly.  I think it's the same assembly: hi-beam, pass flasher, horn, and turn signal switches.
Reassembled everything, no joy.
What is unclear is we don't know if this switch came with your K1100rs handle bar and whether it has ever worked correctly.
You might think it's the same assembly but the K1100 switch part number differs from the K75 switch part number so the connections may differ.

Please clarify what you have.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline stryder

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Re: Handle bar switch assembly
« Reply #4 on: September 14, 2019, 03:11:13 PM »
What is unclear is we don't know if this switch came with your K1100rs handle bar and whether it has ever worked correctly.
You might think it's the same assembly but the K1100 switch part number differs from the K75 switch part number so the connections may differ.

Please clarify what you have.

The switch is mounted on a k1100rs handle bar, but the bike is a modified k75c. The swtich/headlight worked well for 20 years, then the low beam and passing flasher just died.
Southern Ontario, Canada.

Offline Laitch

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Re: Handle bar switch assembly
« Reply #5 on: September 14, 2019, 03:25:37 PM »
In that case, the source of the switch doesn't matter as long as it is wired similarly. Have you tried continuity testing the wires within the switch to look for internal breakage within them? It seems like you're close to finding the fault.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline The Mighty Gryphon

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Re: Handle bar switch assembly
« Reply #6 on: September 14, 2019, 05:37:12 PM »
The switches on our bikes have to handle all the current to the headlamp so they are prone to burned contacts. 

Have you disassembled the switch to the contacts?  Have you cleaned them with Deoxit?  That stuff is very good at fixing electrical whack.  A little polishing with 600 grit wet or dry paper wouldn't hurt.

Regardless of how you proceed, I would recommend getting an Eastern Beaver relay harness for your headlight.  It will greatly improve the reliability of the handlebar switch and increase the light output of the headlight.

http://www.easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

Offline stryder

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Re: Handle bar switch assembly
« Reply #7 on: September 15, 2019, 11:11:26 AM »
The switches on our bikes have to handle all the current to the headlamp so they are prone to burned contacts. 

Have you disassembled the switch to the contacts?  Have you cleaned them with Deoxit?  That stuff is very good at fixing electrical whack.  A little polishing with 600 grit wet or dry paper wouldn't hurt.

Regardless of how you proceed, I would recommend getting an Eastern Beaver relay harness for your headlight.  It will greatly improve the reliability of the handlebar switch and increase the light output of the headlight.

http://www.easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html

Yes, I disassembled the switch and cleaned the headlamp contact points and plates up with some contact cleaner and 2000 grit wet paper. I stated the high beam flasher didn't work, but it does. I lost the little coil spring behind the contact pate for the flasher on first dis- and reassembly, but whipped one up from a ball point pen spring and it works: high beam works, passing flasher works, instrument lights work, horn works, signal flashers work...low beam doesn't work.

Thanks for that link re the headlight wiring harness, but I don't see how it would work with the current situation, i.e. my guess is a defective switch. Or is that the point, i.e. by passes the switch low beam function?     
Southern Ontario, Canada.

Offline stryder

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Re: Handle bar switch assembly
« Reply #8 on: September 15, 2019, 11:14:48 AM »
In that case, the source of the switch doesn't matter as long as it is wired similarly. Have you tried continuity testing the wires within the switch to look for internal breakage within them? It seems like you're close to finding the fault.

Thanks for the suggestion, but what would I check? There are 4 leads at the switch for 43 functions, low, (not working) high beam and flash, (both working) and three wires at the bulb socket. 

Thanks.
Southern Ontario, Canada.

Offline stryder

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Re: Handle bar switch assembly
« Reply #9 on: September 15, 2019, 11:27:57 AM »
So I decided to take a chance and ordered a used switch from flea-bay. Price seemed reasonable to risk. Should take a week to get here. I hope that works. :-)
Southern Ontario, Canada.

Offline Past-my-Prime

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Re: Handle bar switch assembly
« Reply #10 on: September 15, 2019, 11:44:49 AM »
Hope springs eternal!

I've had low beam failure but that was after a disassembly / reassembly of my fairing and the problem was the connection between the light and the wires there. Cleaning and reattaching fixed the problems making me wish I had even skinnier arms.
  • North Shore of Lake Superior
  • 1989 K75 RT

Offline stryder

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Re: Handle bar switch assembly
« Reply #11 on: September 15, 2019, 01:03:55 PM »
Hope springs eternal!

I've had low beam failure but that was after a disassembly / reassembly of my fairing and the problem was the connection between the light and the wires there. Cleaning and reattaching fixed the problems making me wish I had even skinnier arms.

So I just passed by your way last week.......in my car. :-( Was supposed to be on my bike. I noticed the no low beam condition as the bike was warming up at 4:30 a.m.last Sunday, all packed and ready to go. Was supposed to go to Vancouver. :-( Turned back at Regina. Just toooooo boring. But,  Sault St.Marie to TB and back? Worth the drive.

I'm doing that too, i.e. disconnecting and reconnecting every connector I can see under the tank and at the light. 

Prepping the bike, I replaced some lights in the dash pod, and made some soldering repairs to the wiring in behind. I don't think that has anything to do with the low beam suddenly not working as all the lights in the dash work. I have read that the low beam can just stop working like this on my model bike, i.e. high beam etc. still works and a different assembly is recommended by some. Hope it works. :-)
Southern Ontario, Canada.

Offline John Lang

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Re: Handle bar switch assembly
« Reply #12 on: September 15, 2019, 05:19:56 PM »
Is power available to the low beam side of the bulb? Could the bulb itself be whack?
  • Ottawa, ON Canada
  • 1987 K75C

Offline The Mighty Gryphon

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Re: Handle bar switch assembly
« Reply #13 on: September 15, 2019, 07:30:44 PM »
I had the low beam filament in my headlight burn out once.  Actually, it has burned out in all the bikes I have owned.  I read somewhere that the high beam filament is designed to work for more hours than the low beam.  I have no idea why.

If the bulb is good, I would be probing around in the switch to see exactly where I was losing the voltage for the low beam.  There has to be power going in as long as the high beam works properly.  Find where the power is not passing through and you can correct the problem.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

Offline stryder

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Re: Handle bar switch assembly
« Reply #14 on: September 16, 2019, 06:38:38 AM »
Is power available to the low beam side of the bulb? Could the bulb itself be whack?

That's the first thing I thought and so the first thing I did was swap to a spare bulb and same thing.

Nothing stopping me from trying a new, third bulb  guess. :-)
Southern Ontario, Canada.

Offline stryder

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Re: Handle bar switch assembly
« Reply #15 on: September 16, 2019, 06:50:45 AM »
I had the low beam filament in my headlight burn out once.  Actually, it has burned out in all the bikes I have owned.  I read somewhere that the high beam filament is designed to work for more hours than the low beam.  I have no idea why.

If the bulb is good, I would be probing around in the switch to see exactly where I was losing the voltage for the low beam.  There has to be power going in as long as the high beam works properly.  Find where the power is not passing through and you can correct the problem.

So the switch is working much, much better mechanically than it was after I cleaned it up, i.e. movement of the toggle is smooth and free whereas before it was very stiff would bind on the flasher as I rarely use the high beam or passing flasher. The switch's wiring goes from the bar to the wiring loom under the tank, where I checked the multi-pin plug/connector and it was free of corrosion etc. .

I tried checking continuity, but, there are four contact points at the switch and three leads to the bulb. Don't know what it would mean to confirm no continuity other than to lay open the switch's wiring or the wiring in the main loom to look for a short/break? 
Southern Ontario, Canada.

Offline stryder

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Re: Handle bar switch assembly
« Reply #16 on: September 16, 2019, 11:48:39 AM »
Is power available to the low beam side of the bulb? Could the bulb itself be whack?

WOW...just freaking WOW!!! What are the odds of having 2 bad bulbs?

I bought a new H4 bulb, and it worked !!! Slap my ass and call me Sally!!!

The bulb I had in the bike was maybe a year old and was working. The replacement bulb I had was working when I last used it. Both show no, I mean zero signs of being burnt out, i.e. all filaments etc. *are solid/attached*, no discoloration, no noise when shook They both look *perfectly fine*!

Slipped the new bulb in...low beam works. Went deep into my spare bulb stash in my emerg travel kit, and that works as well.

Wow, lesson learned I guess. Even if you have 2 bulbs that look good, and the low beam doesn't work on either, try a new third!!!

At least I now have a refurbished switch. lol...(and a used spare on the way :-) )

Live and learn.

Thanks for all the feedback.  :1thumbup
Southern Ontario, Canada.

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