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   K100 Speedometer dead Empty K100 Speedometer dead Thu Aug 13, 2020 1:35 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
Hi all,

I parked the K up Friday last week and all was well. I've come back to it today and there isn't a flicker of life from the speedo needle or the odometer, the trip meter never moved a micron and the needle seems stuck to its stop. The only thing that I can think of is that we've had a few very hot days here, can it affect the clocks like this? The bike does live outside.

I see someone else here had an intermittent failure of their speedometer and he replaced a capacitor, I can believe the heat may have finished mine off. Otherwise has anyone got some suggestions for starting points? Everything else works fine (for now!). Do the sensors in the final drive ever fail?

I have googled but most people seem to have working speedos and dead odos, which is not my problem..

Thanks for any pointers! scratch


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL
http://justbikethings.blogspot.co.uk/
    

2Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Thu Aug 13, 2020 2:01 pm

Dai

Dai
Life time member
Life time member
Have a squinty down at eye level with the instrument panel. Yes, the faces do warp (lots of warped Aussies on the forum) and you should be able to see if that's the problem.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

3Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Thu Aug 13, 2020 2:04 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
Wouldn't the odometer still count though? By the way it does have a cover on it so it's not directly in the sun.

More googling reveals our own BooG did have a FD sensor stop working but no mention under what circumstances and if it was at all intermittent before failure. Mine has not been intermittent.

I'll go have a squint though..

EDIT: Squint suggests it's still flat Crying or Very sad


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL
http://justbikethings.blogspot.co.uk/
    

4Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Thu Aug 13, 2020 2:58 pm

Laitch

Laitch
Life time member
Life time member
When I bought my moto, the speedometer faceplate veneer and the tachometer faceplate veneer in the instrument cluster were warped enough to stall needle movement. The odometer continued to record mileage accurately. When the faceplates were replaced with plates that had flat veneer, both the speedometer and tachometer resumed accurate functioning.


__________________________________________________
1995 K75 81,000 miles
K100 Speedometer dead Usa-lo10
    

5Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Thu Aug 13, 2020 4:14 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
The tacho still works fine, it's just the speedo and odo are dead as a dodo. I've seen the resistance of the FD sensor should be around 280 ohms, I'll start by checking that. I think I just might have a spare sensor in the spare FD I bought a couple of years ago, here's hoping!


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL
http://justbikethings.blogspot.co.uk/
    

6Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Thu Aug 13, 2020 7:10 pm

robmack

robmack
Life time member
Life time member
Try Karamba (or now known as K-diag) to isolate the problem to either the sender, cabling or gauge cluster. Faster than random parts swapping.

https://www.k100-forum.com/t2038-karamba-speedometer-calibration-program-tutorial


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
http://k75retro.blogspot.ca/
    

7Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Sun Aug 16, 2020 3:44 am

gabriel

avatar
Platinum member
Platinum member
@Snod Blatter wrote:The tacho still works fine, it's just the speedo and odo are dead as a dodo. I've seen the resistance of the FD sensor should be around 280 ohms, I'll start by checking that. I think I just might have a spare sensor in the spare FD I bought a couple of years ago, here's hoping!

Hi

I had a similar problem and I somehow managed to find a solution.
I suggest first check the speedometer sensor at the rear wheel. Trace the wire back to the connector and use a multimeter to check dc voltage. Slowly turn the rear wheel with your hand and you will see a change in the readout on your multimeter. Make certain you set your multimeter to measure mv.
As you slowly turn the wheel, the readings will change in sync with the wheel rotation.
Next check is inside the instrument gauge. Have a close look at the metal tracks and clean them. Carefully Remove the rubber cover At the main connector without breaking the pins and look for broken tracks. Give them a clean with deoxit.
Carefully remove the long thin board at the bottom right of the instrument gauge. I think it’s the amplifier board.
Check both sides, especially the copper tracks.


Good luck....


__________________________________________________
;BMW; 1984 BMW k100..frame number 6228?
1992 BMW K75s
    

8Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Mon Aug 17, 2020 1:26 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
It finally stopped raining so I had time to go poke the bike with a multimeter. First was the FD sensor on the bike with the connector hidden just behind the right side panel, refreshingly easy to get at and a lot easier than setting up a Karamba testing station (sorry robmack!). As far as I can tell it's open circuit and there's no voltage pulse when the wheel was spun. I dug out the spare FD and stuck the multimeter on that, a consistent 290 ohm reading results. I think we have a winner!

I'll report back again after swapping it, which depends on when it stops threatening to rain again.. Not a big job I know but I'm not getting wet for it Laughing


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL
http://justbikethings.blogspot.co.uk/
    

9Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Mon Aug 17, 2020 2:12 pm

MartinW

MartinW
Life time member
Life time member
You can test I without getting wet. Either wave a powered up soldering iron near the sender without melting it. Watch to see if the speedo needle moves. Alternatively place the bike on the centre stand, make sure the rear wheel is well clear of the ground, start the bike up put it in gear and rev it gently and watch the needle. Don't let it drop off the stand while doing this otherwise you'll have another doorway into your shed.
Regards Martin.


__________________________________________________
K75s Hybrid
    

10Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Mon Aug 17, 2020 9:24 pm

gabriel

avatar
Platinum member
Platinum member
@Snod Blatter wrote:It finally stopped raining so I had time to go poke the bike with a multimeter. First was the FD sensor on the bike with the connector hidden just behind the right side panel, refreshingly easy to get at and a lot easier than setting up a Karamba testing station (sorry robmack!). As far as I can tell it's open circuit and there's no voltage pulse when the wheel was spun. I dug out the spare FD and stuck the multimeter on that, a consistent 290 ohm reading results. I think we have a winner!

I'll report back again after swapping it, which depends on when it stops threatening to rain again.. Not a big job I know but I'm not getting wet for it Laughing

If the speedometer does not work and the arrows do not turn off automatically but only by acting on the appropriate command, the sensor may be in cause and must be checked first. This obviously does not apply if, as often happens, operation resumes by moving the instrument panel or the wiring with your hand.
To check the sensor, disconnect the connector in the swingarm area and connect it to a tester in the mV position; by turning the wheel the tester must mark a voltage. If not, the sensor has failed. 
This was copied from a manual written in Italian and is available in the “how to” section of this forum.


__________________________________________________
;BMW; 1984 BMW k100..frame number 6228?
1992 BMW K75s
    

11Back to top Go down   K100 Speedometer dead Empty Re: K100 Speedometer dead Sat Aug 22, 2020 2:34 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
@MartinW wrote:You can test I without getting wet. Either wave a powered up soldering iron near the sender without melting it.
Pshh I can do better than that..
K100 Speedometer dead J61WVVB
With the spare FD hooked into the connector the needle twitched with excitement when the hub was spun. So, the old sensor was removed and the sensor from the spare FD fitted in its place. The speedo now works just fine, phew.

For future reference, if you have around 81816 miles on the bike and the speedo and odo suddenly stop working, possibly after a spell of abnormally hot weather, check your speedo sensor! It also seems to be quite rare that the speedo needle itself stops moving, it seems much more resilient than the odo which has been the bane of many people's lives.

Thread [SOLVED] K100 Speedometer dead 723598 And yes the stickers do help to hold the fairing together Cool


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL
http://justbikethings.blogspot.co.uk/
    

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