The more time i spend on here the more questions i have answered, even ones that i havent asked yet. But today sadly i feel as though i might be asking a stupid question. Every now and again, (more so when its hot) my speedo drops out on me. The tach works fine and i can ride the bike but i dont have any indication of speed and thus my odometer ceases to function. Does anyone know where the instrument cluster gets ths simformation and is there potentially an easy fix. This happened on my dads old r60 but that was just a matter of lubing up the cable that attached to the cluster. This on the other hand is more or less out of my league. The instrument cluster is electronic, so basically i have no idea whats wrong with it. Any assistance would be appreciated.

Longing to know how far ive been, and how large my ticket is going to be

Joel

The early K bikes which yours is are subject to condensation in the instrument cluster, later models were fitted with Goretex vents which helped quite a bit.

This subject has been addressed a number of times on this list. Use the search function with the search term instrument cluster and that will return a number of suggested items. Have a read of those plus while you are at it get yourself some DeoxIT because you are going to need it to treat the connections in the cluster and all the rest on the bike as well. Any bike which is over 20 years old will have corrosion and oxidation on its electrical connectors so giving them a go with DeoxIT will restore them to as new as they can be and stop further damage.
Regards,
K-BIKE

Hi Joel,

Just to get you started, the speedo gets a reading from the sensor that's sits on top of the final drive (FD). You will see a black thingo (technical term...try to keep up) with an electrical cable coming out of it. This thingo is held in place by a hex-head bolt. Undo do it and wiggle it out.
Clean it with kero, metho or similar, wipe it nice and dry and reinsert it.

Follow the electrical cable from the FD until you come across a connector. Separate the connector and clean the hell out of the male and female bits. This is a known problem area. As K-BIKE said, use DeoxIT on all electrical connections on the bike.

See how you go after that.

The coonector Blakey mentions, is a two pole connector with a brown and yellow wire which you find at the frame tube under the right side cover.

Inge K.

don't forget the board in the speedo itself could be loose too

Thanks for clarifying that Inge!

I had the same problem recently and discovered that the wire from the sensor at the rear wheel was rubbing against the tire. It had worn through one of the wires which would make a connection every once in a while causing an intermittent working situation.

The good news is that it was a simple fix.

So, check that wire placement!

I also had the same problem, and all I had to do was spray the multiplug at the back of speedo with DeOxit, and she was all better.

And when we speak about the multiplug connector.................
When having problem with connection in this area, check the bottom of the connector pins.

The pins is pressed/clinched to the plastic frame with the circuit film between.
At this spot it seems like a galvanic reaction occurs, due to the different materials.

I think this is in the first place caused by the condensation problems in the instruments,
and this area get less heat and air to dry up again, with good help from the rubber gasket
to keep the moisture in place.

Haven`t got problem with the speedometer pins at this spot so far, but a lot of others.
This reaction also got help from the current flow, so usually it starts at the pins which
got highest flow...positive terminal and light.

Inge K.

yes true inge ...probably gavanic reaction ...hapens a lot in dc type circuits ....ask any marine electrician ....a long time ago antenna rotators (tv type ) used to corrode away the terminals till they tried ac supply to the drive motors ...with much better results long term

had you thought of high silver content paint ...like the stuff they use on rear window demisters in cars ....works for many ...um unsolderable type connections.... like keyboard membranes in computers ...print head flexible cables and many other situations ......just a thought

Thanks Charlie! I haven`t tried conductive paint to cure this problem, but it was on my list of possible solutions.
The reason to that didn`t use this was if it didn`t lead to satisfactory results, it would have been difficult (using strong solvents) to clean the area before using other metods.

Inge K.

If the situation gets placed in the "too hard" basket, as it did with me there is a non BMW solution. I got a Sigma brand pushbike computer..cheap, trip, odo, clock, stop watch, average speed etc.....works off a magnet on front wheel. My speedo and odo are the only things that still don't work on the real instruments...problems include broken cogs, corrosion and wires damaged damaged by previous owner when he got frustrated with the issues.

I strongly suggest you try the DeoxIT treatment with the G5 spray and when dry give it a spray of the Caig S5 spray as a long term protectant.
Regards,
K-BIKE

I ended up soldering wires from the connector to the various parts inside and that fixed it.

I split the speedo/tacho casing on mine as per advice on this forum - very slight twist to all connectors and a good coating of DeOxit and the job's a goodun - speedo hasn't missed a beat since. It took me about 1½ hours start to finish

Good result Krambo.
88KE