BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down   Starter issues – K100RS Empty Starter issues – K100RS on Sat Dec 21, 2019 4:40 am

GeoffP63

GeoffP63
active member
active member
 
     
1985 K100RS (55,000 ks)
BEP 3.0 with Acewell 2853 speedo
Neutral light is active
 
Hi all,
My apologies for this long post but I wanted it known that I have given this problem a lot of time and effort before coming here for assistance.


There is an abundance of information on this subject and although I have followed the advice from numerous posts from Robmack, RicK G and Holister to name a few, the problem below persists.
Bike started & ran perfectly prior to rebuild.


When pushing the start button the starter initially gets power (starter relay clicks but motor will not turn over.)


I can hear the starter engage and can see the alternator move slightly, confirming it is moving the engine.
The starter relay appears to be getting power initially (+12v to control coil terminals) but won’t hold the internal contacts closed to allow it to turn over.
This was confirmed when I removed the cover from the starter relay.
+12v to starter relay from rear terminal (to battery), +12v from front terminal (to starter motor) when start button is pushed.


When I manually close the internal control contact point the motor turns over strongly until I release it.  


This happens irrespective of whether the ignition is on or off or if the kill switch is in the run or stop position.


On a few occasions it did turned over but then continued turning until I removed the earth lead.
Aware that the starter relay might have been damaged by an undercharged battery, I installed a new starter relay and new fully charge 290 CCA battery, problem persists.


Another observation, although may not to related ;
When the ignition is turned on and the headlights switch on, lights remain on when the kill switch is in the run or off position and remain on when the start button is pushed, although do flicker when start button is pushed (I assumed the Load shedding relay should turn it off?) Someone can hopefully confirm if this is normal behaviour.
 Checked Load shedding relay with +12v (Internal click) and Multimeter confirms ok. Swapped Horn & load shedding relay anyway
Tested load shedding relay – jumper from starter motor connection to ground whilst ignition on and kill switch in run position (did not push starter button :blush:)
If lights are switched on when doing the above, lights stay on.
  
What I’ve done so far;

  • Brand new fully charged 290 CCA battery

  • Checked all battery connections are clean and tight

  • Neutral light is working on new speedo, also confirmed Clutch switch is working

  • New starter relay

  • Checked starter motor – cleaned commutator, brushes well within spec, bench tested with direct connection to battery

  • Start button/kill switch – Thoroughly cleaned all contact points and checked for continuity

    from start button to wiring loom and to relays



  • Cleaned and checked ignition switch

  • Checked and cleaned all earth points on frame

  • Unplugged every connector, including under tank (not used Deoxit yet)

  • Removed all relays, cleaned contacts

  • Checked all fuses

 
Any help or suggestions would be much appreciated.
 
Regards,
 
Geoff

    

2Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 9:49 am

Two Wheels Better

Two Wheels Better
Moderator
Moderator
The biggest headache from the starter motor is often dust accumulation from the overworked 'brushes' inside. All manner of odd electrical gremlins can occur. I suggest removing the starter for disassembly and giving it a good clean out. 

Here's a great tutorial from our esteemed Robmack from north of the border in the great white wilds of Canadialand:

Starter Motor Tutorial

Another option is to simply type start motor or starter brushes into the forum's search engine and you will see a plethora of useful info on the subject going back yonks.

Re-read your questions and see that you've already been in there. I suggest the chicken bone dance. It almost always works.


__________________________________________________

1977 R75/7-R100 grey, '87 K100RS red, '93 K11-K12 aka 'Big Block' black, '96 K1100RS black, '98 K1200RS red, '09 K1300GT red, & 2013 R1200RT-Polizia black & white.

    

3Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 10:34 am

Arlina

Arlina
Life time member
Life time member



I can hear the starter engage and can see the alternator move slightly, confirming it is moving the engine.
The starter relay appears to be getting power initially (+12v to control coil terminals) but won’t hold the internal contacts closed to allow it to turn over.
This was confirmed when I removed the cover from the starter relay.
+12v to starter relay from rear terminal (to battery), +12v from front terminal (to starter motor) when start button is pushed.


When I manually close the internal control contact point the motor turns over strongly until I release it.  



On a few occasions it did turned over but then continued turning until I removed the earth lead.
Aware that the starter relay might have been damaged by an undercharged battery, I installed a new starter relay and new fully charge 290 CCA battery, problem persists.


There's 12V, but not enough amp power.
Check with this diagram where connections may fail;

Starter diagram


__________________________________________________
Starter issues – K100RS Eu-log10  K1100RS/LT - R1200RT - R1100RS (RIP) - Cagiva SST 350 Ala Verde
    

4Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 3:34 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
What is the voltage at the terminal on the starter motor when the start button is pressed?

It should be very close to what you are reading on the start relay, if not, there may be a problem in the wire from the relay to the starter.

Another check is the resistance between the terminal on the start relay that goes to the starter and the engine ground point above the gear shift lever.  Take the reading with the ignition OFF.  The resistance should be very low,almost zero and well under 2-3 ohms.  This is a tricky reading because a lot of cheap DVM's have crap leads and connectors that won't allow readings below 5-10 ohms.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

5Back to top Go down   Starter issues – K100RS Empty No go on Sat Dec 21, 2019 6:49 pm

daveyson

daveyson
Silver member
Silver member
Hi,  welcome.

When you say rebuild, what's been done? 

You've done some good tests,  the Load Shed Relay failed your test, as the lights stayed on,  even if it passed a low load test. It might not be able to power a headlight with battery power to 85 and 86. Did the horn relay also fail your test?

Did the light cut out when you manually closed the starter relay?

The LSR relies on the starter for earth. 

Two quick tests.  With an earth jumper wire to starter relay pin 85, does it go? 

With a power jumper wire to pin 86, does it go?

I like all the above ideas,  especially the chicken dance,  that was all the excuse I needed to YouTube it.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

6Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 8:14 pm

GeoffP63

GeoffP63
active member
active member
@Two Wheels Better wrote:The biggest headache from the starter motor is often dust accumulation from the overworked 'brushes' inside. All manner of odd electrical gremlins can occur. I suggest removing the starter for disassembly and giving it a good clean out. 

Here's a great tutorial from our esteemed Robmack from north of the border in the great white wilds of Canadialand:

Starter Motor Tutorial

Another option is to simply type start motor or starter brushes into the forum's search engine and you will see a plethora of useful info on the subject going back yonks.

Re-read your questions and see that you've already been in there. I suggest the chicken bone dance. It almost always works.

Thanks for your response.

The Chicken dance started sometime ago.  Very Happy

Although I did clean out the starter and commutator, I didn't clean the brushes.
They were in spec length wise but I'll go back in and give them and clean as well.

Regards,

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

7Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 8:18 pm

GeoffP63

GeoffP63
active member
active member

There's 12V, but not enough amp power.
Check with this diagram where connections may fail;

Starter diagram

Thanks Arlina,

I've looked at that wiring diagram so often it's been permanently burnt into my memory.  Smile


__________________________________________________
1985 K100RS
50,000 Ks
    

8Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 8:37 pm

GeoffP63

GeoffP63
active member
active member
@Point-Seven-five wrote:What is the voltage at the terminal on the starter motor when the start button is pressed?

It should be very close to what you are reading on the start relay, if not, there may be a problem in the wire from the relay to the starter.

Another check is the resistance between the terminal on the start relay that goes to the starter and the engine ground point above the gear shift lever.  Take the reading with the ignition OFF.  The resistance should be very low,almost zero and well under 2-3 ohms.  This is a tricky reading because a lot of cheap DVM's have crap leads and connectors that won't allow readings below 5-10 ohms.

Thanks for your response,

Hard to get an accurate voltage reading at the starter as the start relay isn't closed long enough.

Resistance between start relay terminal to battery and ground above the gear lever is 00.01

On the start relay, when I remove the connector from pins 85 & 86 an apply +12v & -12 the bike turns over


Regards,

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

9Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Dec 21, 2019 8:57 pm

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:Hi,  welcome.

When you say rebuild, what's been done? 

You've done some good tests,  the Load Shed Relay failed your test, as the lights stayed on,  even if it passed a low load test. It might not be able to power a headlight with battery power to 85 and 86. Did the horn relay also fail your test?

Did the light cut out when you manually closed the starter relay?

The LSR relies on the starter for earth. 

Two quick tests.  With an earth jumper wire to starter relay pin 85, does it go? 

With a power jumper wire to pin 86, does it go?
Hi Daveyson,

Thanks for your assistance. 

Not sure if you meant jump the pins whilst the connector was still on...

With connector on
Earth jumper wire to relay pin 85 turns the starter motor but only if the ignition is on and the start button is pushed.

Power jumper to pin 86 the bike turns over as soon as connection is made (with the ignition off).

With connector off 
Apply +12v & -12 to both 85 & 86 the starter motor turns over.


Regards,

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

10Back to top Go down   Starter issues – K100RS Empty No go on Sat Dec 21, 2019 11:32 pm

daveyson

daveyson
Silver member
Silver member
Ah ha, an Aussie South of New South.

What was done for the rebuild? 

With the ignition on,  and a jumper wire to 86, does it crank? 

With a test light clip on battery positive, and probe to starter relay 85, is the light on,  and remain on with ignition on? And remain on with start button pushed? 

I spose connections are clean and tight.

To summarise,  your earth jumper test shows the starter relay is working,  and there is power to 86, so I guess it will fail the earth tests to 85.

Your previous tests showed fails at the LSR and the starter relay. 

If it fails the earth tests,  next could be an earth jumper wire from ICU to starter relay. If no luck,  inputs to the ICU. 

And get some electrical contact cleaner. Where abouts in Vic are you?



Last edited by daveyson on Sun Dec 22, 2019 5:58 am; edited 2 times in total (Reason for editing : Summarise)


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

11Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Dec 22, 2019 7:25 am

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:Ah ha, an Aussie South of New South.

What was done for the rebuild? 

With the ignition on,  and a jumper wire to 86, does it crank? 

With a test light clip on battery positive, and probe to starter relay 85, is the light on,  and remain on with ignition on? And remain on with start button pushed? 

I spose connections are clean and tight.

To summarise,  your earth jumper test shows the starter relay is working,  and there is power to 86, so I guess it will fail the earth tests to 85.

Your previous tests showed fails at the LSR and the starter relay. 

If it fails the earth tests,  next could be an earth jumper wire from ICU to starter relay. If no luck,  inputs to the ICU. 

And get some electrical contact cleaner. Where abouts in Vic are you?
Hi Daveyson,

Thanks again for your help so far.

Can you share more details re the ICU Jumper tests?

Rebuild was mainly cosmetic.

Electric wise, I installed a BEP 3.0 and Acewell 2853 and stripped out some wiring no longer required.
I always referred to the main wiring diagram before doing this.

Speedo has neutral light working, all brake, headlight and indicator are working.

Start relay was working until after the earlier tests. 1 step forward, one and a half steps back.. Now the start button isn't activating the starter relay at all.
Pulled the starter motor out again, cleaned the brushes and bench tested again all ok.

Reinstalled S/motor, still nothing. Checked plug from pin 85/86 and +12v is present when start button is pushed.

I'll check it all again in the morning and might order a new LSR in case this is the culprit.

Is Deoxit the gold standard or is there something else you can recommend?

BTW - Horn relay tested same as LSR

I'm located in Ormond, South East suburbs.

Thanks again.

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

12Back to top Go down   Starter issues – K100RS Empty No go on Sun Dec 22, 2019 8:07 am

daveyson

daveyson
Silver member
Silver member
Deoxit is the go.  

With an earth jumper to 85 you got it cranking so everything is working ( I'm assuming you disabled starting for your tests) 

Anyway,  either the ICU is not allowing earth,  or the earth wire from ICU pin 11 to starter relay 85 has failed (or earth to the ICU or another connection has failed if you disturbed them with modifications hopefully) with a jumper wire from 11 to 85 hopefully your bike goes.  Hopefully the ICU is still OK.  But before that if your bike goes with your temporary earth to 85, just leave it at that till your problem is sorted, at least you can ride until then.

Replace the fuses to,  and stuff like that in Bert's guide.



Last edited by daveyson on Sun Dec 22, 2019 8:10 am; edited 1 time in total (Reason for editing : Added last sentence.)


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

13Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Dec 22, 2019 8:11 am

Dai

Dai
Life time member
Life time member
@GeoffP63 wrote:
I'll check it all again in the morning and might order a new LSR in case this is the culprit.
You're obviously very competent with the electrics, so I'm going to say DON'T go and buy a BMW one. Search for a 'Ripca 279495'; same switching action but BMW use DIN 1 standards and the more modern stuff is DIN 2. Check the pin layout; IIRC pins 86 and 30 are reversed compared to DIN 1. A simple case of pop the terminals out of the socket and switch them round. And save a lot of AU$.

I've changed all of my relays for DIN 2. Relays are pretty reliable but it does mean if one goes pop and I need a replacement in a hurry, I can get one from the nearest auto shop.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

14Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Dec 22, 2019 8:37 pm

Two Wheels Better

Two Wheels Better
Moderator
Moderator
The chicken dance: a slightly goofy 'pop' dance primarily done by children and drunken adults at wedding receptions. Result? People fall down laughing and often wake up with a headache but a good time was had by all.

The chicken bone dance: midnight twirling round a blazing fire deep in the bayou with allusions of voodoo, the black arts, and painted men in top hats with 'uncola' deep voices, laughing maniacally. Result? The rusty screw comes loose, the remaining trace of petrol in your tank gets you to the nearest servo, or the smoke is contained inside the wiring loom where it belongs.


__________________________________________________

1977 R75/7-R100 grey, '87 K100RS red, '93 K11-K12 aka 'Big Block' black, '96 K1100RS black, '98 K1200RS red, '09 K1300GT red, & 2013 R1200RT-Polizia black & white.

    

15Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Dec 23, 2019 1:07 am

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:Deoxit is the go.  

With an earth jumper to 85 you got it cranking so everything is working ( I'm assuming you disabled starting for your tests) 

Anyway,  either the ICU is not allowing earth,  or the earth wire from ICU pin 11 to starter relay 85 has failed (or earth to the ICU or another connection has failed if you disturbed them with modifications hopefully) with a jumper wire from 11 to 85 hopefully your bike goes.  Hopefully the ICU is still OK.  But before that if your bike goes with your temporary earth to 85, just leave it at that till your problem is sorted, at least you can ride until then.

Replace the fuses to,  and stuff like that in Bert's guide.
Thanks again for all the assistance so far.

BTW, At this stage the tank is off and empty, although I did try it with the fuel level sender connected and it made no difference. (fuel pump is working)


After running the tests on Pin 85/86 on start relay, for some reason the start relay no longer reacts to the start button. No click at all (with jumpers removed) I only hear the Fuel Injection relay click.


Gremlins are in the system.


I did the tests again and the difference is now when Power jumper applied to pin 86 the bike no longer turns over when connection is made (with the ignition off or on). Previously it turned over as soon as connection is made (with the ignition off).


The Earth jumper wire - to relay pin 85 test results remain unchanged - turns the starter motor only if the ignition is on and the start button is pushed.


With a test light clip on battery positive, and neg probe to starter relay 85, the light is off and remains off with ignition on and remains off with start button pushed.


ICU earth test – no change with a jumper wire from pin 11 on ICU to pin 85 on starter relay.


I read in another post that “The starter and the bike will fire fine even if you have a bad load shed relay.  The load shed relay has NOTHING to do with the bike starting or running” Is this correct?


LSR test – headlight switch to off
Jumper from starter terminal to ground whilst IGN on, kill switch to Run, headlight switch off -  Headlight does not turn on.


Same test but with headlight switch to on – Lights are on before connection to ground and remain on when connected to ground.


Test result the same when LSR swapped with horn relay.


When the internal connection of starter relay is manually closed (cover off) - If lights are switched on they remain on.    


This is so frustrating as it's the only thing stopping me from finishing the build and actually riding the bike!
Self indulgent photo below make it worth while.

Regards,
Geoff
Starter issues – K100RS K100rs10


__________________________________________________
1985 K100RS
50,000 Ks
    

16Back to top Go down   Starter issues – K100RS Empty No go on Mon Dec 23, 2019 2:05 am

daveyson

daveyson
Silver member
Silver member
True,  I still like chicken dance though, and they say it increases fuel from 91 octane to 98 proof,  and I believe it too,  a million petrol sniffers can't be wrong. 

Normally I listen to Neil Diamond,  but because of the extra Yeehaaa I got from the chicken dance,  last night I went up a notch to Nutbush City Limits, and stuff like that.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

17Back to top Go down   Starter issues – K100RS Empty No go on Mon Dec 23, 2019 2:52 am

daveyson

daveyson
Silver member
Silver member
The earth jumper test again shows the relay, 86, 30 and 87 are all working,  leaving only 85 as suspect.  The test light test proves 85 has failed. 

You say the fuel pump works so  find out if the cylinders are getting fuel and spark.

The ICU test,  let's face it,  it's not looking good for the ICU. But try the wishful ideas like the wiring disturbed,  especially if you have extra fuses in the relay box. 

The bike should run,  even with the LSR  removed, it's only a helper. 

I was thinking of a different headlight test.  It doesn't matter now.  The LSR gets earth from the starter,  which gets it from the starter relay,  but there isn't any.  Don't worry about the LSR,  do the no start problem first.

I don't think that BEP type stuff is your problem, but I'm clueless about stuff like that.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

18Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Dec 23, 2019 3:36 am

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:The earth jumper test again shows the relay, 86, 30 and 87 are all working,  leaving only 85 as suspect.  The test light test proves 85 has failed. 

Just to clarify, the test to Pin 86 has changed, so starter motor no longer turns as it did when I first did the test.
"The Earth jumper wire - to relay pin 85 test results remain unchanged - turns the starter motor only if the ignition is on and the start button is pushed"

I don't understand why the starter motor & relay aren't t least clicking as they did before. Apart from doing the tests above nothing has changed

You say the fuel pump works so  find out if the cylinders are getting fuel and spark.

I haven't added fuel and connected the tank as I wanted the starter to be properly turning over first.
Are you suggesting I do this and use the jumper to pin 85 to see if it fires up?

If so I will that a go tomorrow.

Thanks again for all your help and suggestions.

The ICU test,  let's face it,  it's not looking good for the ICU. But try the wishful ideas like the wiring disturbed,  especially if you have extra fuses in the relay box. 

The bike should run,  even with the LSR  removed, it's only a helper. 

I was thinking of a different headlight test.  It doesn't matter now.  The LSR gets earth from the starter,  which gets it from the starter relay,  but there isn't any.  Don't worry about the LSR,  do the no start problem first.

I don't think that BEP type stuff is your problem, but I'm clueless about stuff like that.


__________________________________________________
1985 K100RS
50,000 Ks
    

19Back to top Go down   Starter issues – K100RS Empty No go on Mon Dec 23, 2019 5:33 am

daveyson

daveyson
Silver member
Silver member
That's good news that there was no fuel in the tank, so the chances are good that your only problem is an earth failure to 85. 

First it was a partial failure then a total failure. It died slowly not suddenly.  I don't know either why it died slowly, I don't know stuff all about the insides of computers (or the outsides) doesn't bother me if it failed slowly or suddenly, it simply failed.

Yep I recon with a temporary earth and fuel your bike will go,  and you can ride it for a year while continuing your tests. 

When it goes there will be just one more thing to do,  the chicken dance.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

20Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Dec 23, 2019 8:10 am

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:That's good news that there was no fuel in the tank, so the chances are good that your only problem is an earth failure to 85. 

First it was a partial failure then a total failure. It died slowly not suddenly.  I don't know either why it died slowly, I don't know stuff all about the insides of computers (or the outsides) doesn't bother me if it failed slowly or suddenly, it simply failed.

Yep I recon with a temporary earth and fuel your bike will go,  and you can ride it for a year while continuing your tests. 

When it goes there will be just one more thing to do,  the chicken dance.
Haha.
Yep prepared to take baby steps in solving the issue if it actually starts and I can ride it Very Happy

I'll try that tomorrow and report back.

Thanks again.

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

21Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Dec 23, 2019 7:19 pm

cycleman

cycleman
active member
active member
One thing to try is to jump the bike with another 12 Volt car battery.  It it will turn over then, you have found your culprit.  As somebody else posted earlier, you have a voltage drop in the starting circuit.  What that basically means is that you may have 12.6 or so volts at the battery, but that voltage isn't getting to the starter.

I had this happen to me on an old gold wing.  It would start and run if I jumped it with a car battery, but even thought the battery in the bike was brand new and fully charged it would just click the starter relay. I checked the voltage at the wire going to the starter relay from the battery and found that it was 12.6, checked the voltage at the end of the same wire at the starter relay and it showed, just slightly less than 12.6 volts.  There was corrosion somewhere in the wire and when the load came on the wire ( pushing the starter button ) it wouldn't allow sufficient voltage to the starter.  Replaced the piece of positive cable and no more issues. 

Use the VOMeter and test any of the leads from both ends to ground to see if that is what is happening on your bike.

    

22Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Tue Dec 24, 2019 9:00 am

GeoffP63

GeoffP63
active member
active member
Thanks cycleman,
I'll try the jumper battery as soon as I can.
I have installed news cables from battery to ground & starter but they are much longer than standard.
Reason for this is I'm planning on mounting the new battery behind the seat under the cowling.


__________________________________________________
1985 K100RS
50,000 Ks
    

23Back to top Go down   Starter issues – K100RS Empty No go on Tue Dec 31, 2019 4:30 am

daveyson

daveyson
Silver member
Silver member
Here are some tests you may want to do,  which might show that the fault is not in the ICU. 

Draw a picture of the ICU plug as you see it,  with the rubber cover removed.  Number the sockets and include the wire colour codes.  Label 7,4,3,1,14,11, and 9 with negative signs.  Label 6,2 and 10 with positive signs. 

If you're not already using one,  get an LED (computer safe)  test light, they're cheap as chips now.  Here are some test results you should expect to get.

With a test light clip on battery positive, and ignition off:

Probe to 1 (brown) - the light should go on. 
It should also go on with probe to 3,4,7,9,11 and 14.

With test light clip on battery negative:
Ignition off; 6,2 and 10 -light off. 
Ignition on; 6 - off,  2 - on, 10 - on. 
Ignition on,  start button pressed;  6 - on. 

Turn ignition off.
Don't put the probe in any other sockets,  especially not 5 (orange) or 13 (brown)

As I'm about an hour north, another option would be to see if your ICU doesn't start my bike,  it's toast.

I spose I should caution against static electricity. Or better,  since just tracking an earth fail at 11, the loom could be tested with the connector unplugged from the ICU. The drawing should then be done again,  5 and 13 could be taped over as a precaution. The first I would test would be 1. If no luck, then maybe 4, 3,2,6 and 10 until a fault may be found.



Last edited by daveyson on Fri Jan 03, 2020 7:07 pm; edited 1 time in total (Reason for editing : Added last paragraph.)


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

24Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Jan 05, 2020 7:19 am

GeoffP63

GeoffP63
active member
active member
Starter issues – K100RS Img_2013
Starter issues – K100RS Img_2012
@daveyson wrote:Here are some tests you may want to do,  which might show that the fault is not in the ICU. 

Draw a picture of the ICU plug as you see it,  with the rubber cover removed.  Number the sockets and include the wire colour codes.  Label 7,4,3,1,14,11, and 9 with negative signs.  Label 6,2 and 10 with positive signs. 

If you're not already using one,  get an LED (computer safe)  test light, they're cheap as chips now.  Here are some test results you should expect to get.

With a test light clip on battery positive, and ignition off:

Probe to 1 (brown) - the light should go on. 
It should also go on with probe to 3,4,7,9,11 and 14.

With test light clip on battery negative:
Ignition off; 6,2 and 10 -light off. 
Ignition on; 6 - off,  2 - on, 10 - on. 
Ignition on,  start button pressed;  6 - on. 

Turn ignition off.
Don't put the probe in any other sockets,  especially not 5 (orange) or 13 (brown)

As I'm about an hour north, another option would be to see if your ICU doesn't start my bike,  it's toast.

I spose I should caution against static electricity. Or better,  since just tracking an earth fail at 11, the loom could be tested with the connector unplugged from the ICU. The drawing should then be done again,  5 and 13 could be taped over as a precaution. The first I would test would be 1. If no luck, then maybe 4, 3,2,6 and 10 until a fault may be found.

     
Hi Daveyson,
 
Happy New Year to you and anyone else reading this thread.
 
I’ve just returned from an O/S holiday so back into the trouble shooting.
 
Thanks for the info on checking the ICU/wiring etc.  I think I’ve uncovered an issue with the ICU.
 
I decided to inspect the internals of the ICU and discovered a couple of burnt points (see Pics). I believe this may have been caused by accidentally shorting something when jumping pin 85 & 86. I have a 2nd hand ICU on the way.
 
A quick recap;
 
Prior to conducting the pin 85 & 86 tests, the start relay and starter motor always reacted to the starter button. Confirmed with the cover off, I could see the internal relay points close for a second and the starter motor briefly react. However it wouldn’t allow the starter motor to continuously run whilst button was held.
 
Now there is no reaction from the start relay or starter motor. The only click comes from the fuel injection relay.
 
Due to this a ran the tests again.
 
Earth jumper wire to relay pin 85 - turns the starter motor (although not vigorously) only if ignition is on and the start button is pushed. This remains unchanged from first time tested.


Now when I connect a power jumper to pin 86 the bike no longer turns over as soon as connection is made, as it did when the test was first done. (with the ignition off or on).

Whilst waiting for the new ICU, I'll run the tests with the ICU unplugged

I now have have some Deoxit and have applied to all connection.

Thanks again for all your assistance.

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

25Back to top Go down   Starter issues – K100RS Empty No go on Sun Jan 05, 2020 5:34 pm

daveyson

daveyson
Silver member
Silver member
Hi Geoff,  happy new year. 

There are further tests on Bert's guide.  If all the tests are good,  hopefully your problem is gone with the new ICU. Still worth looking at the original one though. Are you referring to the two black triangular bits in the photos? Are the different colours in the second photo due to reflection? Maybe trace the main pins back as far as you can,  especially where they join to the board. What does the other side of the board look like, especially at any suspect spot. I guess that's pin 1 (or 8 ) on the bottom left, it looks like it got hotter than any other one. 

Good luck with the tests.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

26Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Jan 05, 2020 11:37 pm

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:Hi Geoff,  happy new year. 

There are further tests on Bert's guide.  If all the tests are good,  hopefully your problem is gone with the new ICU. Still worth looking at the original one though. Are you referring to the two black triangular bits in the photos? Are the different colours in the second photo due to reflection? Maybe trace the main pins back as far as you can,  especially where they join to the board. What does the other side of the board look like, especially at any suspect spot. I guess that's pin 1 (or 8 ) on the bottom left, it looks like it got hotter than any other one. 

Good luck with the tests.


Tested with the connector plugged into ICU
With a test light clip on battery positive, and ignition off:

Starter issues – K100RS K100-210
 
Probe to 1 (brown) - the light should go on.  Correct
It should also go on with probe to 3,4, Correct
7 - Test light is off but Speedo lights up as if ignition is on and fuel injection relay clicks
9 - Test light is on but faint, Speedo lights up, no relay clicks
11 - Nothing
14 - Test light is on but faint, Speedo lights up, no relay clicks
 
With test light clip on battery negative: All tests ok
Ignition off; 6,2 and 10 -light off. 
Ignition on; 6 - off,  2 - on, 10 - on. 
Ignition on,  start button pressed;  6 - on. 
 
Tested with the connector unplugged from the ICU. 
With test light clip on Pos+ 
Probe to 1 (brown) - Light on 
Wasn't sure if clip remains on Pos+ for 4, 3,2,6 and 10, so thought I'd better check with you...


__________________________________________________
1985 K100RS
50,000 Ks
    

27Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Jan 05, 2020 11:50 pm

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:Hi Geoff,  happy new year. 

There are further tests on Bert's guide.  If all the tests are good,  hopefully your problem is gone with the new ICU. Still worth looking at the original one though. Are you referring to the two black triangular bits in the photos? Are the different colours in the second photo due to reflection? Maybe trace the main pins back as far as you can,  especially where they join to the board. What does the other side of the board look like, especially at any suspect spot. I guess that's pin 1 (or 8 ) on the bottom left, it looks like it got hotter than any other one. 

Good luck with the tests.

I have circle the points that appear to have been burnt.

I haven't yet worked out how to get under the board. I'm guessing the plug points need to be removed somehow to allow the board to lift off the case?

Starter issues – K100RS Icu_bo10


__________________________________________________
1985 K100RS
50,000 Ks
    

28Back to top Go down   Starter issues – K100RS Empty No go on Mon Jan 06, 2020 1:42 am

daveyson

daveyson
Silver member
Silver member
You don't have to repeat the tests unplugged, since you have the results already. It passed all your tests except some of the earth outputs. It is receiving earth from 1, but failing to provide earth to 11, that's the main problem. I think the new ICU will solve your problem. To be extra cautious, you might want to do Bert's tests.

You might want to try to fix it,  maybe you only need to reflow solder, or something simple like that. 11, 7 and 1 deserve a close look,  I think.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

29Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Jan 06, 2020 4:46 am

GeoffP63

GeoffP63
active member
active member
@daveyson wrote:You don't have to repeat the tests unplugged, since you have the results already. It passed all your tests except some of the earth outputs. It is receiving earth from 1, but failing to provide earth to 11, that's the main problem. I think the new ICU will solve your problem. To be extra cautious, you might want to do Bert's tests.

You might want to try to fix it,  maybe you only need to reflow solder, or something simple like that. 11, 7 and 1 deserve a close look,  I think.

Thanks again for all your advice.
Pardon my ignorance but were can I find Berts tests? Kforum- tech page?


__________________________________________________
1985 K100RS
50,000 Ks
    

30Back to top Go down   Starter issues – K100RS Empty No go on Mon Jan 06, 2020 5:07 am

daveyson

daveyson
Silver member
Silver member
Yep,  under electrical,  troubleshooting the EFI.  If lucky it might just be a poor connection at pin 1


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

31Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Jan 06, 2020 1:40 pm

Nordhaven

Nordhaven
active member
active member
If you haven't already tried jumping your starter from.a car battery I would encourage you not to. The ICU may not be able handle the amps and could fry it. I share this from experience. As for you electrical gremlins I noticed no one has yet mentioned the obvious; double check your engine and electrical grounds. A poor ground can cause many issues that keep a person chasing their tail trying to figure the issue out. Sounds overly simplistic I know, but if you haven't already can't hurt to double check your grounds. And if you have jumping off a car battery, I recommend checking your ICU is still ok.

    

32Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Tue Jan 07, 2020 12:08 am

GeoffP63

GeoffP63
active member
active member
@Nordhaven wrote:If you haven't already tried jumping your starter from.a car battery I would encourage you not to. The ICU may not be able handle the amps and could fry it.  I share this from experience.  As for you electrical gremlins I noticed no one has yet mentioned the obvious; double check your engine and electrical grounds. A poor ground can cause many issues that keep a person chasing their tail trying to figure the issue out.  Sounds overly simplistic I know, but if you haven't already can't hurt to double check your grounds. And if you have jumping off a car battery, I recommend checking your ICU is still ok.

Thanks Nordhaven,

Thanks for your input.

Interesting you should mention jump starting as I was going to try that when the replacement ICU arrived. 
I won't be doing that now. The battery is new so I doubt it's the issue.

As for ground points, these have been checked and cleaned numerous times during the troubleshooting process.

I believe the current ICU may have been damaged during some of the start relay tests I did (likely my fault).

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

33Back to top Go down   Starter issues – K100RS Empty No go on Tue Jan 07, 2020 4:15 am

daveyson

daveyson
Silver member
Silver member
I'm guessing it might just be a poor connection somewhere. For example the pin 1 solder contact might be 90% broken,  a bit like a rope,  everytime it gets used,  it gets weaker, until total failure, so you probably didn't do anything wrong.

Looking at your earth output tests,  I don't think it's a coincidence that low load pins (eg. 4) passed your test,  high load ( pin 11) totally failed,  and some partial failures in between. Again,  just guessing.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

34Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sat Jan 11, 2020 9:03 pm

GeoffP63

GeoffP63
active member
active member
Hi all,

Ok, so replacement ICU installed and we are back to square one.

When start button is pushed, starter relay clicks, starter motor reacts for a second but doesn't continuously turn.

As Daveyson suggested, I may have disturb something when I cleaned up the wiring loom.

I'm going to unwrap it to see if I can find any issues.

Any her thoughts or advice would e appreciated.

Regards,

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

35Back to top Go down   Starter issues – K100RS Empty No go on Sat Jan 11, 2020 10:42 pm

daveyson

daveyson
Silver member
Silver member
With an earth jumper wire to 85, and fuel in the tank,  see if the bike runs. 

The ICU sometimes deliberately denies the signal to the EFI (for example to prevent damage from over revving, so maybe it needs to read revs or speed or something) I think you mentioned that the speedo doesn't work, but unlikely I spose. 

I would be thinking about doing the earth output tests again, or better do the input tests with the ICU removed. To test earth the test light clip needs to be on battery positive for the light to glow.



Last edited by daveyson on Sun Jan 12, 2020 2:33 am; edited 2 times in total (Reason for editing : EFI comment, inputs comment.)


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

36Back to top Go down   Starter issues – K100RS Empty No go on Sun Jan 12, 2020 8:42 pm

daveyson

daveyson
Silver member
Silver member
Another thought,  are you confident about your rewiring? It would be worth looking at the other test fails to try to understand them.

 For example when I tested pin 7, I expected the test light to go on,  and it did. When you did it the light remained off and the speedo light went on.  What's the go there???

I'm starting to think your rewiring is the problem. Dunno how difficult it would be to reverse your modifications and proceed one step at a time.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

37Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Jan 12, 2020 11:07 pm

GeoffP63

GeoffP63
active member
active member
Hi Daveyson,

I really appreciate the time and thought you have put in to working through this with me. 

Re the wiring, yeah I started thinking about what I may have done wrong.

It wasn't so much of a rewire as a clean up, re routing & rewrap.

I unwrapped the loom and carefully removed wiring not needed, but only after checking the wiring diagram.
Things like the connection for special equipment, additional instruments, heated grips and Bulb monitoring relay.
Bulb monitoring not required with BEP 3.0

Never the less, yesterday I completely removed and unwrapped the loom again to trace connections.

I'm pretty confident I have continuity through all wiring whilst it is disconnected. I paid particular attention to all the grounds.

I'll redo the earth output tests as suggested. Then I'll put some fuel in and jump pin 85 to see what happens.

I must admit this has nearly beaten me  Crying or Very sad and I'm considering taking it to an Auto Electrician.

My guess is it will be hard to find one that understands K100's.

Geoff



Last edited by GeoffP63 on Sun Jan 12, 2020 11:46 pm; edited 1 time in total


__________________________________________________
1985 K100RS
50,000 Ks
    

38Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Sun Jan 12, 2020 11:45 pm

GeoffP63

GeoffP63
active member
active member

Test to back of ICU plug whilst plugged into ICU redone.

With a test light clip on battery positive, and ignition off:
 
Probe to Pin 1 (brown) - the light should go on.  As per previous test - Correct

Probe to Pin 3,4, As per previous test - Correct

Pin 7 - Test light now on, no speedo lights but fuel injection relay clicks (previously nothing but Speedo lights up as if ignition is on and fuel injection relay clicks

Pin 9 - Test light now on, no speedo lights (previously Test light was on but faint, Speedo lights up, no relay clicks

Pin 11 - Test light now on (previously nothing)

Pin 14 - Test light now on, no speedo lights  (previously Test light is on but faint, Speedo lights up, no relay clicks


__________________________________________________
1985 K100RS
50,000 Ks
    

39Back to top Go down   Starter issues – K100RS Empty No go on Mon Jan 13, 2020 4:12 am

daveyson

daveyson
Silver member
Silver member
Goodo,  that's a big improvement. On your previous earth tests, the test light failed to light multiple times, now it lights every time,  still some weird bits though. 

I don't mind at all, finding an excuse to run some tests on a brick. 

It seems like one of those unneeded wires might actually be needed.  There should be instructions somewhere on how to BEP a brick. Just wait,  there are members here who have done it or know how to.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

40Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Jan 13, 2020 4:53 am

GeoffP63

GeoffP63
active member
active member
Thanks for the recommendations on Electrical work Daveyson.

Given the distance from me and not having a trailer, I might persist for a bit longer.

The wires removed all terminated at an unused plug and piggy backed from a plug housing another wire of the same colour.

I can't see how removing them could be creating this issue but happy to be told otherwise.

Re the BEP, once again I don't believe this is the issue.  

In fact I removed it and plugged in the original instrument cluster and the same problem happens.

Onwards and upwards.


__________________________________________________
1985 K100RS
50,000 Ks
    

41Back to top Go down   Starter issues – K100RS Empty No go on Mon Jan 13, 2020 7:35 am

daveyson

daveyson
Silver member
Silver member
The ECU also denies earth to the starter relay,  unless it detects that it's running at under 710RPM.

Maybe install the removed parts one at a time,  until it goes.



Last edited by daveyson on Sun Jan 19, 2020 3:09 am; edited 2 times in total (Reason for editing : Deleted starter and coil comments.)


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

42Back to top Go down   Starter issues – K100RS Empty Re: Starter issues – K100RS on Mon Jan 13, 2020 7:45 am

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
I don't know enough about this subject but one thing in the back of my mind is that if a K thinks its overheated it will not start. 

Is it possible it is not receiving the right temperature signals from the temperature sensor [behind the radiator] and thinks its over heated?


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 100,380 miles
1983 K100RS 0011171 Fricka 606 29,495 miles Damn K Pox Its a Bat outta Hell No 33,600 miles
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum