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   Gauge issues Empty Gauge issues on Tue Apr 30, 2019 5:08 pm

Martcarl

Martcarl
active member
active member
Hello!

After some hours of measuring, thinking, testing and talking to members on this forum I now try to describe my problem here to see if anywone have experience this peculiar problem before. 

I started in November -18 to build a scrambler of a K100 RS-88, and it will soon be ready for the road. However, I have now a problem whit the aftermarket speedometer gauge (Velona Daytona) which behave strange when the engine is running. 

The speedometer gets signals from the rear wheel as it should and register incomming signals when the ignition is on and I manually spin the rear wheel, but when the engine start the incoming signals rushes away even thougt the rear wheel is still. 

To isolate the problem I dissconected all of the cables not having anything to do whit the speedometer function (horn, turn signals, tacometer, gear cables etc) from the TGPI V5 board (Thanks to Robmack) but still I get this strange behavior in the gauge. 

So I still get this problem even if I only have connected the 
1. speedometer in 
2. speedometer out
3. +12 V 
4. Ground 


If someone has ideas about what can cause these phenomena then I am grateful for all the help I can get. Is the gauge mabye defective?


I have tried to reroute the cables (thanks for the tips robmack) to aviode interference, but with no success.


In the video below you see the speedometer in setup mode counting signals from the speedsensor. The rear wheel is still but a lots of signals is registered.


BR/Martin




    

2Back to top Go down   Gauge issues Empty Re: Gauge issues on Wed May 01, 2019 12:43 pm

Stumpy

Stumpy
Silver member
Silver member
Have you tried an external power supply? Use another battery for power, not connecting to the bike, if the speedo works then you will know it has something to do with the power feed from the bike.

    

3Back to top Go down   Gauge issues Empty Re: Gauge issues on Wed May 01, 2019 2:54 pm

tinyspuds

tinyspuds
Silver member
Silver member
I only ask because you haven’t mentioned doing it, have you run the calibration set up? I think these gauges are a bit random until that’s done...


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s.
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

4Back to top Go down   Gauge issues Empty Re: Gauge issues on Wed May 01, 2019 4:30 pm

Martcarl

Martcarl
active member
active member
@Stumpy wrote:Have you tried an external power supply? Use another battery for power, not connecting to the bike, if the speedo works then you will know it has something to do with the power feed from the bike.


Hmm. Can of course be woth the shoot. Do you mean I just connect an external battery to the TGV5 board?

    

5Back to top Go down   Gauge issues Empty Re: Gauge issues on Wed May 01, 2019 4:45 pm

Martcarl

Martcarl
active member
active member
@tinyspuds wrote:I only ask because you haven’t mentioned doing it, have you run the calibration set up? I think these gauges are a bit random until that’s done...

Yes! When I try to do this setup I see this hysterical frequency from the speed sensor. The sensor should give 6 signals per revolution of the rear wheel if I have understand it correctly. I get maby 20 signals per second even if the wheel is still when the engine is running. If the engine is off it works as it should.  

I have now also find out that the sensor is picking upp signals also when I remove it from its position (still connected). I just need to hold it near the frame to get this phenomenon with the "fake signals". 

Was doing some ground measuring between the battery negative and the frame this evening. All measurements showed at low ohm numbers (0.1 - 0.7 Ω)

To be continued....   study

    

6Back to top Go down   Gauge issues Empty Re: Gauge issues on Wed May 01, 2019 8:36 pm

Laitch

Laitch
Life time member
Life time member
@Martcarl wrote:The speedometer gets signals from the rear wheel as it should and register incomming signals when the ignition is on and I manually spin the rear wheel, but when the engine start the incoming signals rushes away even thougt the rear wheel is still.
Are you using resistor spark plug wire, or resistor spark plugs?


__________________________________________________
1995 K75 73,000 miles
Gauge issues Usa-lo10
    

7Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 3:37 am

Martcarl

Martcarl
active member
active member
@Laitch wrote:
@Martcarl wrote:The speedometer gets signals from the rear wheel as it should and register incomming signals when the ignition is on and I manually spin the rear wheel, but when the engine start the incoming signals rushes away even thougt the rear wheel is still.
Are you using resistor spark plug wire, or resistor spark plugs?

I have brand new Bosch X5DC spark plugs on, (bought from motorworks). If a measure resistans on the spark plug wires I get about 5 kΩ. So I guess I have resistor spark plug wire?

    

8Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 6:52 am

Michael Sydney

Michael Sydney
Silver member
Silver member
Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.


__________________________________________________
Living in the past! K100 '83 and R65 '83.
    

9Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 7:26 am

Martcarl

Martcarl
active member
active member
@Michael Sydney wrote:Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.


Funny is that a colleague suggested exactly the same thing about the alternator just an hour ago.  This may be the evening's exercise. I plan to pull the alternator out of its mount so it is still plugged in but not spinning.
I can ofcourse also measure if there is AC voltage.

The "soldering trick" is working as it should and give me a stable result on the gauge.

Thank you for the tips!

I come back with the result tonight. (Swedish time) Very Happy

    

10Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 3:58 pm

Martcarl

Martcarl
active member
active member
@Stumpy wrote:Have you tried an external power supply? Use another battery for power, not connecting to the bike, if the speedo works then you will know it has something to do with the power feed from the bike.


I did connect the gauge, TGPI board and sensor to a own battery today but could not see any difference. It behaved like before, no change. scratch

    

11Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 4:14 pm

Martcarl

Martcarl
active member
active member
@Michael Sydney wrote:Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.

Started to measure voltage on the alternator, no AC voltage, just a perfect 13 V DC. Also removed the alternator from its position, still connected to the bike and started the motor. no change. 
Gauge issues 259495

Next step (if no one have more tips) is to visit my friend and try his speed sensor. 
 
Question to you guys who have tried the "soldering iron trick". Do you need to remove the sensor and hold the soldering iron under it to get signals or do you just need to come close to the sensor?  I think mine is picking  up signals as soon I come near the sensor.

    

12Back to top Go down   Gauge issues Empty Re: Gauge issues on Thu May 02, 2019 4:42 pm

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
@Martcarl wrote:
@Laitch wrote:
@Martcarl wrote:The speedometer gets signals from the rear wheel as it should and register incomming signals when the ignition is on and I manually spin the rear wheel, but when the engine start the incoming signals rushes away even thougt the rear wheel is still.
Are you using resistor spark plug wire, or resistor spark plugs?

I have brand new Bosch X5DC spark plugs on, (bought from motorworks). If a measure resistans on the spark plug wires I get about 5 kΩ. So I guess I have resistor spark plug wire?

That's correct for the 2v engine, resistor leads and no R in the plug code.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 98,780 miles
1983 K100RS 0011171 Fricka 29,495 miles Damn K Pox Its a Bat outta Hell No 32,600 miles
    

13Back to top Go down   Gauge issues Empty Re: Gauge issues on Fri May 17, 2019 11:09 am

Bumblebee

Bumblebee
Silver member
Silver member
@Michael Sydney wrote:Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.
 DING DING DING!!!  (Chime sound from a TV game show.)  My educated guess is that the tachometer is "seeing" ripple from the alternator.  The false signal is most likely coming in the power wire.  As said before (right above) it might be excessive ripple from the alternator with a defective rectifier. It will still charge the battery at a lower rate, but my cause problems just as you are seeing.

Try this, take a 470 uf capacitor and hook it from the power lead to ground, this might solve the problem.  This is a test, only a test see of the problem is reduced, or eliminated.

Bumblebee

http://Bugsmashers.org/phpbb
    

14Back to top Go down   Gauge issues Empty Re: Gauge issues on Mon May 20, 2019 5:36 pm

Martcarl

Martcarl
active member
active member
@Bumblebee wrote:
@Michael Sydney wrote:Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.
 DING DING DING!!!  (Chime sound from a TV game show.)  My educated guess is that the tachometer is "seeing" ripple from the alternator.  The false signal is most likely coming in the power wire.  As said before (right above) it might be excessive ripple from the alternator with a defective rectifier. It will still charge the battery at a lower rate, but my cause problems just as you are seeing.

Try this, take a 470 uf capacitor and hook it from the power lead to ground, this might solve the problem.  This is a test, only a test see of the problem is reduced, or eliminated.

Bumblebee

Thank you for the tips Bumblebee! 

If this is the problem, shouldn't this phenomenon then also stop when I completely disconnect the generator? At one point I also tried to feed the circuit board from a separate battery, but with no success.


We will try to change the circuit board now to see if it helps.


Br/Martin

    

15Back to top Go down   Gauge issues Empty Re: Gauge issues on Mon May 20, 2019 9:55 pm

Bumblebee

Bumblebee
Silver member
Silver member
@Martcarl wrote:
@Bumblebee wrote:
@Michael Sydney wrote:Is it possible you have a failed diode in the alternator/rectifier? That could send stray AC voltage around the bike possibly triggering the Speedo. Check the voltage of the alternator output with your meter set to AC.

Also, have you checked the Speedo using the heating element of a mains powered soldering iron in close proximity to the rear hub sender?  You need ignition on but not motor running. This will send regular pulses to the instrument and should display a constant speed consistent with the mains frequency.
 DING DING DING!!!  (Chime sound from a TV game show.)  My educated guess is that the tachometer is "seeing" ripple from the alternator.  The false signal is most likely coming in the power wire.  As said before (right above) it might be excessive ripple from the alternator with a defective rectifier. It will still charge the battery at a lower rate, but my cause problems just as you are seeing.

Try this, take a 470 uf capacitor and hook it from the power lead to ground, this might solve the problem.  This is a test, only a test see of the problem is reduced, or eliminated.

Bumblebee

Thank you for the tips Bumblebee! 

If this is the problem, shouldn't this phenomenon then also stop when I completely disconnect the generator? At one point I also tried to feed the circuit board from a separate battery, but with no success.


We will try to change the circuit board now to see if it helps.


Br/Martin

"If this is the problem, shouldn't this phenomenon then also stop when I completely disconnect the generator?"


Yes, it should, I'll bet that there is something (interfering signal) that's getting into the gauge cluster.  You would think that disconnecting the alternator would do it, maybe the ignition system?  If this were my bike it'd have me running around in circles trying to find it.  I have had issues with the instrument cluster too!  In 31 years (how old mine is, it's an '88) things do start to have issues, but overall the bike has been solid!



BB

http://Bugsmashers.org/phpbb
    

16Back to top Go down   Gauge issues Empty Re: Gauge issues on Mon May 20, 2019 11:40 pm

MartinW

MartinW
Life time member
Life time member
Disconnecting the wiring doesn't stop the alternator from generating.
Regards Martin.


__________________________________________________
K75s Hybrid
    

17Back to top Go down   Gauge issues Empty Re: Gauge issues on Tue May 21, 2019 1:59 am

Bumblebee

Bumblebee
Silver member
Silver member
@MartinW wrote:Disconnecting the wiring doesn't stop the alternator from generating.
Regards Martin.
No, it wont.  But if you remove the battery wire it will eat the diodes for lunch!

BB

http://Bugsmashers.org/phpbb
    

18Back to top Go down   Gauge issues Empty Re: Gauge issues on Tue May 21, 2019 2:44 am

chris846

chris846
Life time member
Life time member
20 pulses per second (post 5) is 1000rpm tickover speed-ish. Maybe the gauge is faulty and not isolating the tacho signal input from the speedo input?
Can you run the gauge with the tachometer input disconnected?

Edit: re-read the thread, and you've already tried it with tacho input disconnected. I'd still suggest that the approx 20 Hz frequency of the interference suggests an ignition/engine source rather than the alternator. If the speedo sensor detects this when held near the frame (post 5) then it's maybe a grounding issue with the ignition - the frame is carrying the ignition voltage. You could try sticking temporary extra grounding all over the ignition side of things - engine/frame/coils/battery? Pay close attention to the small-gauge brown wires onto the coils.


__________________________________________________
The Longest Lunch
    

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