Author Topic: Please help identify a yellow wire and a weird switch, thank you!  (Read 441 times)

Offline jiigan

  • Curious
  • Posts: 9
Hey Guys,
I picked up an 85 k100rs and started stripping it down. Came across a weird yellow wire that is out of place and a weird switch under the left side handlebar. Could you please help identify.

Thank you
  • Los Angeles, CA
  • 1985 BMW K100RS

Offline Scott_

  • Forum Moderator
  • ^ Quintessential Motobricker
  • Posts: 1882
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #1 on: January 01, 2019, 09:56:46 PM »
I'd pull of the T cover and see how the wire is connected.
It could be alternate power to the HES sensors, it could be a anti-theft "kill switch", it could be most anything.....
Can't tell 100% till you know how each end is connected, both behind the cover and what is connected on the back of the switch.
  • My Garage
Ride safe.


1997 K1100LT 0302488
1995 K1100LT 0302044
Garmin StreetPilot 2820
Garmin Zumo 550
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Chaos

  • ^ Quintessential Motobricker
  • Posts: 2259
  • Mars needs women!
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #2 on: January 01, 2019, 09:58:37 PM »
Have you tried flipping the switch when it's running?
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
2012 Ural 2WD sidecar (BMW's bastard step child)

Online Laitch

  • ^ Quintessential Motobricker
  • Posts: 5929
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #3 on: January 02, 2019, 07:18:05 AM »
Have you tried flipping the switch when it's running?
:clap: Please video that moment, jiigan.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline jiigan

  • Curious
  • Posts: 9
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #4 on: January 02, 2019, 01:05:17 PM »
Thanks for chiming in. Have not tried to mess with switch while running as I only found it after taking the bike apart. I will open the cover and see where the wire hooks up. The switch has 3 positions it can switch to as well as 3 wires in the back.
  • Los Angeles, CA
  • 1985 BMW K100RS

Offline jiigan

  • Curious
  • Posts: 9
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #5 on: January 02, 2019, 11:08:44 PM »
I'd pull of the T cover and see how the wire is connected.
It could be alternate power to the HES sensors, it could be a anti-theft "kill switch", it could be most anything.....
Can't tell 100% till you know how each end is connected, both behind the cover and what is connected on the back of the switch.
Here is the picture of the cover removed and the back of the switch, any ideas?
  • Los Angeles, CA
  • 1985 BMW K100RS

Offline Scott_

  • Forum Moderator
  • ^ Quintessential Motobricker
  • Posts: 1882
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #6 on: January 03, 2019, 07:06:51 AM »
Well, looking at the t cover spot, the wire doesn't connect to the HES so that throws out the thought of a security kill switch idea....... and it looks like it does not connect to the switch, so there are 2 different things to sort here...
Does your bike have a water temp gauge?
Follow the yellow wire to the end, I'd almost bet that it was added for a water temp gauge sensor. If I'm not mistaken water temp gauges were not stock on older RS bikes.

As far as the switch, does your bike have heated grips on it now?
  • My Garage
Ride safe.


1997 K1100LT 0302488
1995 K1100LT 0302044
Garmin StreetPilot 2820
Garmin Zumo 550
"One who does not ask questions is ashamed to learn" Danish proverb

Online Martin

  • ^ Quintessential Motobricker
  • Posts: 3562
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #7 on: January 03, 2019, 12:30:23 PM »
The switch is next to the steering lock, so I'm guessing either anti theft kill switch or an alarm.
 Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Andy FitzGibbon

  • ^ Motobrick Curious
  • Posts: 105
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #8 on: January 19, 2019, 09:35:37 PM »
Maybe a high altitude switch for the Jetronic unit? The wire routing wouldn't suggest that, but I thought I would...

Andy
  • Montrose, WV
  • 1985 K100RS, 1972 R75/5, 2012 Suzuki DR650

Offline daveson

  • ^ Motobrick Curious
  • Posts: 81
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #9 on: January 20, 2019, 03:34:01 AM »
Look under the water oil /pump to see what the yellow wire connects to.

Under the t cover it's running parallel to a brown green wire.  That wire has a single connector, looking at the wiring diagram that's for the oil pressure light, so oil pressure gauge another possibility.
  • victoria australia
  • current; 1986 bmw k100rt, '88 k100rt, '91 k100rt, '92 k75s '96 kawasaki vulcan 1500 Past;v star 650, kawasaki klx250, yamaha tt250

Offline The Mighty Gryphon

  • ^ Quintessential Motobricker
  • Posts: 4106
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #10 on: January 20, 2019, 10:42:37 AM »
Where is the end of the yellow wire?  Three weeks and still you haven't told us where it comes from and where it goes.  How the are we supposed to tell you what it's for?

Here's my guess based on what I've seen so far.  The switch is for a hyper drive that runs off two battery packs.  The switch lets you select Low power or high power for the hyper drive.

The yellow wire could be for reading the intermolecular spectromatic status of the plasmatron ferdorator in the hyper drive.  If the plasmatron gets too reverse fluxed, the drive goes into overload and there is no telling where you will come out.  That could be dangerous.  Has anyone removed the turbo vortex bifurcator?  That's another place where the yellow wire might go. 
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '92K100RS White, '94 K75S Dakar Yellow
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'94 K75S "Cheetos"
'91 K100RS "Moby Brick Too

Online Laitch

  • ^ Quintessential Motobricker
  • Posts: 5929
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #11 on: January 20, 2019, 12:29:23 PM »
Here is the picture of the cover removed and the back of the switch, any ideas?
Describe exactly the colors of each wire and which wires are joined together at each plug terminal. The dirty condition of the wires in the photo doesn't aid in their identification on a schematic.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline The Mighty Gryphon

  • ^ Quintessential Motobricker
  • Posts: 4106
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #12 on: January 20, 2019, 12:40:33 PM »
Describe exactly the colors of each wire and which wires are joined together at each plug terminal. The dirty condition of the wires in the photo doesn't aid in their identification on a schematic.

C'mon, Laitch, that's what makes this so much fun.  Use your creativity.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '92K100RS White, '94 K75S Dakar Yellow
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'94 K75S "Cheetos"
'91 K100RS "Moby Brick Too

Online Martin

  • ^ Quintessential Motobricker
  • Posts: 3562
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #13 on: January 20, 2019, 04:10:47 PM »
Duhh :idea2: it goes to the Flux capacitor. He has hit the switch and gone back in time, that's why he is not answering. He is currently being chased by Velociraptors and once safe he'll answer. :sip:
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline natalena

  • ^ Proficient Motobricker
  • Posts: 161
Re: Please help identify a yellow wire and a weird switch, thank you!
« Reply #14 on: January 20, 2019, 07:00:53 PM »
Duhh :idea2: it goes to the Flux capacitor. He has hit the switch and gone back in time, that's why he is not answering. He is currently being chased by Velociraptors and once safe he'll answer. :sip:
Regards Martin.

Or, he could be minutes into the future, reading these posts, and thinking "I really stepped in it this time." I think it's a "gift" from the engineers who designed the brick, many of whom spent their later years designing wee-toys with intricate bits for Kinder Eggs.
  • East of Joshua Tree
  • 1987 K75s #0919

Offline mlytle

  • ^ SuperNatural Motobricker
  • Posts: 931
LOL...with the references to "Back to the Future" here....I just saw a DeLorean sitting in the "for sale" lot at a local Army Post.  soo tempting to put a spare blender on the roof...
  • alexandria, va
  • 92 K75s, 94 K75s, 96 K1100RS SE (custodian), 09 K1300s
Marshall
Project Thread "K75s Midlife Refresh"
http://www.motobrick.com/index.php/topic,7810.0.html

Tags: