Sigh.
I tried to fix one problem and now I have two.

I've had my 1989 K100RS Special Edition for about three years now.  When I got it the speedometer worked about 90% of the time.  About eight months ago that dropped to 0% of the time.  I cleaned the speed sensor at the final drive, cleaned and lubed the connections all the way up to but not including the actual speedometer itself.  I was going to wait till winter to pull it and give it a good going over.
At the beginning of this season I took the bike into a mechanic on an unrelated issue but also asked him to check the speedo.  He stated that the speed sensor was faulty.  Off to eBay I went and found a used one in England and had it shipped.  This whole process took months.  The one from England had a different plug than the original on the bike so, knowing my original speed sensor was garbage, I cut the wire on the speed sensor side of the plug with the intention of simply wiring the new sensor into the old wire.  Well. The new sensor had a very simple two wire set up.  Just two wires.  The original sensor wire has an odd arrangement that I've never seen.  There is an insulated wire wrapped with a wound copper sheath wrapped with a silver strand wire.  Huh?  

How do these three wires connect to the two wires of the new sensor?  

Not being able to figure that out, just to see if it worked I stuffed the two wire set up directly into the female end of the plug still wired into the bike and still the speedo doesn't work.  Maybe the new sensor is faulty?  Maybe the speedo itself is the issue?

But now the second and more pressing problem:  Coinciding with cutting the speed sensor wires, now the ABS lights flash.  I've reset the ABS several times before and am aware of the procedure.  According to posts from 2012, the speedometer/speed sensor are supposed to be a completely separate systems from the ABS so one should not affect the other.  After I go through the reset procedure and take the bike for a spin, the ABS light and the warning light flash in unison.  Just in case the speedo and ABS are linked, I tried every wiring combination including wiring back in the old sensor and the ABS still won't reset.  If the old speed sensor was faulty, why did the ABS still work?

Added issue:  Just after I cut the speed sensor wire, the bike fell over just outside my garage.  I only mention this is because in the 2012 thread I quoted above the fellow did the identical thing so there may be a connection.  I checked the battery and it's right up to power but I put it on the charger anyway.  Still the ABS won't reset with any combination of wiring I can do.

So, ABS won't reset (priority) and how to wire in a new speed sensor two wire into the old three wire.  I'm guessing the speedo issue is in the speedometer itself.





Any suggestions from the learned ones would be great.
Darrin

The ABS sensor is mounted on the rear caliper and the speed sensor is nounted into the rear drive housing just behind the shock mounting bolt.
AFAIK there is only 1 type of 2 pin plug for K100 8V and the K100 16v and K1100 have a different 2 pin connector.
By the look of the wires you have opened the ABS sensor cable. The speedo sensors have 2 yellow wires.
The connector for the 8V bikes is the same connector as the brake switch, choke switch and the blinker connectors in the mirrors of the RS.
The ABS connector is blue and the same as the fuel tank connector.

RicK G wrote:The ABS sensor is mounted on the rear caliper and the speed sensor is nounted into the rear drive housing just behind the shock mounting bolt.
AFAIK there is only 1 type of 2 pin plug for K100 8V and the K100 16v and K1100 have a different 2 pin connector.
By the look of the wires you have opened the ABS sensor cable. The speedo sensors have 2 yellow wires.
The connector for the 8V bikes is the same connector as the brake switch, choke switch and the blinker connectors in the mirrors of the RS.
The ABS connector is blue and the same as the fuel tank connector.

-The speedo sensor have one yellow and one brown wire.
-The brake/choke/clutch switches have round contacts in the connector,
the speedo sensor have flat contacts arranged as a T in the connector.
.....................................................................................................
I do agree that the wire in the photos seems to be for the ABS sensor.

Double sigh.

You are, of course, correct.  I did cut the ABS wire.  How, pray tell, could that of happened (besides me being an idiot?)?  Instead of tracing along the wire from the speed sensor to the plug, I just pulled on the wire from one end and watched what moved.  That plug moved.  I pulled on the wire in that plug and the speed sensor moved.  I'll try to upload a video of it so you only think I'm half an idiot.
BUT I connected the new speed sensor wires to the correct plug and the speedo works!

But now I still have to reattach the ends of the ABS wires.  Referring to the photos I first posted, how does the wiring work?

D

nvboy wrote:But now I still have to reattach the ends of the ABS wires.  Referring to the photos I first posted, how does the wiring work?

The silver coloured wire on the outside of the copper sheat seems to be
connected, as it seems to be no insulation between them.
On the other hand a shield is normaly only connected to ground in one end.
.........
My guess is that center wire is signal, the silver and copper is ground.