I have a 1990 K100RS that does work (I rode it up from Leicester) but the battery etc were loose and the Motronic Unit upside down so I was fixing all of that when I could not get it to restart.

I was checking that there was a spark at the plugs (following the instrructions in my Clymer Manual to remove and ground a spark plug) when the starter stopped turning, strange clicking sounds emanated from the relay area and everything went dead except for the clock.

When the ignition is on I get intermittant clicks from the starter relay for the first few seconds. The lights do not work, the panel lights are not working nor are any of the dials/warning lights.

The portal instructions say that I can test the starter relay by connecting a meter across two terminals - but there are 4. 2 are screwed down and 2 are plugged in.

I seem to be going backwards from trying to sort out a simple problem so would like to take advice from an expert(s)

Many thanks

Zara

Oh - and the fuses all check out ok

There are two relays in play when you start the K. There is also a Load Shed relay which cuts the power to the lights and other functions when you hit the start button. While it can go wrong the more common one to go wrong is the Starter relay.

However moving around the Motronic unit may have disturbed the plug connector which can generate strange evens and which you need to check is correctly seated. Mine also has an earth wire on it but its a K1100 and not sure if its the same.

Battery issues like loose or loose terminal may have left you with a poor charge and Ks do not like that so I would also go and run full check on the battery condition.

You don't say where in Leicester but its possible if the K was sitting for a while the battery is past it so a test is important.

Did you get a Clymer or Haynes with the K or do you have one?

Your reference to 1990 and Motronic suggests its a 16v K, are we correct in assuming this?

Get the battery out and have it load tested before you do anything else.   This is a new to you machine and you need to determine if the battery has reached the end of it's life.  You are wasting your time trying to troubleshoot electrical issues when the battery is gone.

The clicking you hear may be the load shed relay trying to energize, or the ABS relay, which clicks when you turn on the ignition.  Unless you are pressing the start button, I doubt that the clicking you hear is the starter relay.

A guy down the road from me sells lawnmower batteries....one went in a K1 and it cost less than €50.

He has also sold me two batteries for my Ks for the same money.

He always has them because he keeps them for golf carts.

Two things I do with any K after I get it.....check the battery, buy a new one if in doubt. The one time I didnt....it died long after.

Second thing is a new clutch cable irrespective of how its working. My new RS I hadn't got around to it so it broke about 3 weeks ago. Do the same with yours too and use a BMW cable.

92KK 84WW Olaf wrote:

Your reference to 1990 and Motronic suggests its a 16v K, are we correct in assuming this?

Yes, you are correct. The battery if fine, I insisted on a new one and a full service as the bike had done only 500 miles since it was last MOT'd in February 2012. Prior to that it had lain unused in a garage since 2003.

Having studied various wiring diagrams, manuals and this forum this afternoon, I consider that the Load Shedding Relay must be in part, if not totally, the cause of the latest problems so I have ordered a new one (costs less than £12). A Starter Relay is much more expensive so hopefully I will not need one of them.

A bought the Clymer manual, BMW K-Series-1985-1997 off Amazon a couple of weeks ago. I see from the cover that Clymer is a division of Hayes Publishing Group so it should be quite good.

I had been looking for an older BMW for about a year and seen some utter rubbish in that time, so was quite please to find this one, even though it is not a boxer, which are becoming very expensive for 1990 era ones.

I am hoping to go to Germany on it next year for a rally that I shall be attending as many of our club members ride older BMW's

How many thousand km or miles?

You can swap the horn relay or the fan relay for the load shed relay

volador wrote:How many thousand km or miles?

20K miles from new

Thank you for the tip about relays - my new one should be here tomorrow.

May consider a starter motor cleaning also known cause of electrical gremlins

Starter Motor Cleaning Tutorial

Renewal of heat sink compound/paste on ignition amplifier wouldn't hurt either

https://www.k100-forum.com/t12498-most-overlooked-preventative-maintenance-on-early-4vs-k100rs4v-k1-1993-k1100

New relay arrived this morning, fitted and all ok again (for now)

Excellent news.......now for travel plans.

I would replace the clutch cable too, keep the old one for a spare.

My RS came with 29,000 miles, two owners of a certain age, first 18 years, second 17 years in which it sat in a nicely heated boat shed for 17 years, did 7,000 miles in that time but during which most of the seals tyres etc etc did the usual perishing. It had got a new clutch cable in that time so I took a small risk and decided to leave it in as it was super silky. But it broke. I always replace that cable on any bike so this time it bit. You can happily ride a K with no clutch cable.

Another thing that WILL die is the water pump. I think yours will too so just be aware of it. If you are good with them, buy in and have the parts. Some parts have gotten very expensive due the deterioration in the value of sterling.

Brilliant!
some links for the future
Check parts compatibility with "BMW MAX Microfiche", BOBS BMW, REAL OEM

https://shop.maxbmw.com/fiche/PartsFiche.aspx

https://shop.maxbmw.com/fiche/PartsSearch.aspx

https://www.bobsbmw.com/store/microfiche/BrowseSeries.aspx

https://www.realoem.com/bmw/select.do?kind=M&arch=1

Cross reference parts like Bosch pn#'s, etc....  http://partsplusecat.com/


Top 3 vendors for your parts needs plus Capital Cycle

https://www.beemerboneyard.com/

https://www.euromotoelectrics.com/

https://www.tills.de/

Headlight relay stuff if you chose to add one

https://www.motobrick.com/index.php?topic=268.0

http://www.motobrick.com/index.php/topic,4962.msg30932.html

http://culayer.com/product/matchbox-headlight-relay/

http://easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html
 Eastern Beaver site is a great reference for electrical connectors,plugs, etc... somethings are cheaper on ebay


http://www.kforum-tech.com/Tech-page.html

http://www.kforum-tech.com/electrical/EFI/bike-wont-start-EN.htm

http://www.kforum-tech.com/Downloads/electrical/diagrams/interactive_diagrams.htm

http://dws.x10host.com/K100.Tshoot.Start.pdf


duck forum member

http://kbikeparts.com/index.htm

http://www.kbikeparts.com/classickbikes.com/ckb.tech/ckb.new2k.htm

http://www.kbikeparts.com/classickbikes.com/ckb.tech/ckb.tech.toc.htm


http://www.eilenberger.net/K75S/IgnitionSwitch/

http://www.verrill.com/moto/moto.shtml

this site has a lot of good info and breakdown pictures in the tech and tech resources sections thou for K1100 alot of the parts are on K75 & K100

http://www.k11og.org/forum/index.php?sid=2df953dde5715fd9001fbe69edec5ad0

https://ibmwr.org/index.php/k-bike-tech-articles/

This site has all kinds of technical specifications on all the BMW models    http://www.bmbikes.co.uk/mechanicalpages/kseriesmechanical.htm

http://largiader.com

Thank you all for your most helpful advice.