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1Back to top Go down    How to get a cheap eBay Speedo to work on Fri Jan 13, 2017 12:19 am

Jacod

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I recently put on one of those cheap eBay speedos on my K100 and to my surprise I got it all to work, I even used the OEM speed sensor. I did so by trawling through various forums for hours on end. Especially this one and the MotoBrick forum. 

I haven’t got the gear position indicator to work yet. I have to start it with the clutch in and the N light doesn’t illuminate because of this. I am hoping to use one of RBM’s TGPI boards for this (let me know if it will work? Cheers)


To hopefully save any future tin bums some time I have explained below how I managed to get the speedo to work. 


First of all there seems to be two types of these cheap eBay speedos on the market that have differently colour coded wires so I’m not going to put up what colour went to where. The basic wire up is pretty simple you just need to decode their useless instructions. 


Unfortunately you can’t wire the tacho strait into these cheap speedometers and you need to make a filter using a capacitor and a resistor as mentioned on another thread http://www.k100-forum.com/t8232-electrical-trouble-mounting-aftermarket-digital-speedo in this forum. The circuit mentioned in that thread didn’t work for me at first, so I replaced the mentioned capacitor with a 10uf 23v polarised capacitor. Other than that the circuit was the same. 

I also needed to change my settings to 4 cylinders in the ‘hidden settings’ for this to work (see how below)

To access the hidden settings press and hold the button on the back for a while before you turn the ignition on, continue holding once you have turned the igntion on until the ‘hidden menu’ comes up. Short press the button to make a change. Wait without pressing anything for the flashing number to cycle to the next 
Press and hold the button again to cycle through the settings and save any changes. 

For my speedo the hidden menu items corresponded to the following:
Menu 1 is the circumference of the rear wheel (tyre) in mm ( I played around with mine, it is now quite accurate when set to 2060) you can calibrate your speedo using a 50 or 60hz soldering iron turned on and placed close to your speed sensor pick up as mentioned in another thread. To change it simply reduce or increase the circumference size accordingly.
Menu 2 is the number of magnetic sensors you have attached to your wheel (set this to 6 if using OEM speedo sensor).
Menu 3 is the number of cylinders (set to 4)
Menu 4... I'm not sure but it could be the resistance setting for the fuel gauge (didn’t change it)
Menu 5 is to reset the Odometer (not trip meter)

https://www.youtube.com/watch?v=NSXYYkXvISw shows you how to access the hidden menu. 


The other thing that won’t work off the bat is the fuel gauge. You will need to wire your aftermarket speedometer fuel gauge wire to the yellow wire of your accessories connector under the tank. Not all models have this accessory connector and if yours doesn’t you're probably outta luck. For me, after wiring it to this yellow wire it worked perfectly without changing any of the ‘hidden’ settings. 


To get the speedo to work using the OEM sensor you can use the motometer board trick as mentioned in another thread https://www.motobrick.com/index.php/topic,8017.msg59081.html#msg59081. To wire it up follow RBM’s instructions: 

BE - (an input) goes to Yellow wire coming from the sensor in the rear drive
"-" - goes to ground.  Also connect the Brown wire from the sensor in the rear drive to this terminal (this means there are two ground wires connected to this)
BA - (an output) goes to the speedo input on your gauge
"+" - goes to a source of switched +12V power



I also quickly designed and 3D printed a case to connect this which I fitted under the tank which works nicely. See pictures




Things got a little tricky when you want to add some extra warning lights. (A side note; you need a battery indicator light for the battery to charge…) Some of the wires for the warning lights are negatively polarised (see https://docs.google.com/spreadsheets/d/1qF1-ECuyT1TT5L72CG9wYYxpeZr1PPonn0LED-_cvD4/edit#gid=0 ) meaning if you wired them up like you think you would a normal circuit they won’t work. The trick to get these ones to work is to wire a good source of positive switched DC to the anode, and connect cathode to the corresponding wire.
I used a very basic LED and resistor combo to get this to work. And yes the battery charges.  See below




Check out my video of it working on YouTube

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica} p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px} p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; line-height: 16.0px; font: 12.0px Helvetica} p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; line-height: 16.0px; font: 12.0px Helvetica; min-height: 14.0px}
 

    

nods

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Thanks a lot Jacod, very helpful!


__________________________________________________
Chassis number0025951
Vehicle code0504
SeriesK589
ModelK 100 RT 84 (0504 ( 0505 )
Body typeK 100 RT 84 (0504
Catalog modelECE
Production date1985 / 01
Engine0514)
Transmission
Steering
CatalyzerNONE
    

nods

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Jacod wrote:

Things got a little tricky when you want to add some extra warning lights. (A side note; you need a battery indicator light for the battery to charge…)

Hi Jacod, I'm after a little more info on this point, if you don't mind.

I could have sworn I'd read at some point about needing an incandescent light to make something work but never found that reference again.

What does the above mean?  I've removed the original instrument cluster and will only have a few LED warning/indicator lights on the new speedo.  Do I need to have an old school bulb somewhere for the charging circuit to work?

Cheers for any info,
Nods


__________________________________________________
Chassis number0025951
Vehicle code0504
SeriesK589
ModelK 100 RT 84 (0504 ( 0505 )
Body typeK 100 RT 84 (0504
Catalog modelECE
Production date1985 / 01
Engine0514)
Transmission
Steering
CatalyzerNONE
    

Dai

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Nice job!


__________________________________________________
'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)
    

mike d


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nods wrote:
Jacod wrote:

Things got a little tricky when you want to add some extra warning lights. (A side note; you need a battery indicator light for the battery to charge…)

Hi Jacod, I'm after a little more info on this point, if you don't mind.

I could have sworn I'd read at some point about needing an incandescent light to make something work but never found that reference again.

What does the above mean?  I've removed the original instrument cluster and will only have a few LED warning/indicator lights on the new speedo.  Do I need to have an old school bulb somewhere for the charging circuit to work?


Nods

Generally you would require a suitable wattage bulb to 'excite' the alternator. This means to enable the charging circuit to be kick started.

Led bulbs do not provide the required resistance to trigger this excitation, although it is sometimes found that revving the bike engine above say 3000 revs will produce the same effect.

Mike



Last edited by mike d on Sun Jan 15, 2017 8:05 pm; edited 1 time in total (Reason for editing : erasing crap editing!)

    

nods

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mike d wrote:
nods wrote:
Jacod wrote:

Things got a little tricky when you want to add some extra warning lights. (A side note; you need a battery indicator light for the battery to charge…)

Hi Jacod, I'm after a little more info on this point, if you don't mind.

I could have sworn I'd read at some point about needing an incandescent light to make something work but never found that reference again.

What does the above mean?  I've removed the original instrument cluster and will only have a few LED warning/indicator lights on the new speedo.  Do I need to have an old school bulb somewhere for the charging circuit to work?


Nods

Generally you would require a suitable wattage bulb to 'excite' the alternator. This means to enable the charging circuit to be kick started.

Led bulbs do not provide the required resistance to trigger this excitation, although it is sometimes found that revving the bike engine above say 3000 revs will produce the same effect.

Mike
Thank you Mike.  Does this mean a small resistor with a similar resistance to a light bulb would do the same job?


__________________________________________________
Chassis number0025951
Vehicle code0504
SeriesK589
ModelK 100 RT 84 (0504 ( 0505 )
Body typeK 100 RT 84 (0504
Catalog modelECE
Production date1985 / 01
Engine0514)
Transmission
Steering
CatalyzerNONE
    

7Back to top Go down    Re: How to get a cheap eBay Speedo to work on Sun Jan 15, 2017 10:25 pm

RicK G

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All you need is a 12V 3W light bulb


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

Jacod

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Nods.

I too was under the impression that I would need to add a resistor to simulate the same load as the bulb would in the original circuit. I had read this on various other threads too. However, when I was wiring it up I thought I would give it a shot with just the LED and the 0.5w 350Ω resistor (as wired up in the diagram) to my absolute surprise it worked. The battery light comes on when the battery is low, and it turns off when it's charging. I double checked it was charging by putting a multimeter across the battery terminals and revved the bike a bit... and sure enough it charges. 

Not entirely sure why but it works for me.

    

Dai

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Almost certainly residual magnetism. I have one alternator here that switches on at about 1500rpm and stays on at tickover with just an LED (no resistor) as the indicator. As it's a '12 volt' LED there's some form of resistor built into it which will help but I've no idea what rating it is.


__________________________________________________
'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)
    

10Back to top Go down    Re: How to get a cheap eBay Speedo to work on Tue Jan 17, 2017 6:50 am

nods

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Thanks everyone, doesn't sound too daunting now.

Cheers,
Nods


__________________________________________________
Chassis number0025951
Vehicle code0504
SeriesK589
ModelK 100 RT 84 (0504 ( 0505 )
Body typeK 100 RT 84 (0504
Catalog modelECE
Production date1985 / 01
Engine0514)
Transmission
Steering
CatalyzerNONE
    

11Back to top Go down    Re: How to get a cheap eBay Speedo to work on Thu Jan 19, 2017 4:59 pm

Jacod

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12Back to top Go down    Re: How to get a cheap eBay Speedo to work on Thu Jan 19, 2017 5:48 pm

nods

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Jacod wrote:Link to motometer case http://www.thingiverse.com/thing:2042596
Very cool, thanks mate. I've no experience with 3D printing - do I download the plan and take somewhere that has a 3D printer?


__________________________________________________
Chassis number0025951
Vehicle code0504
SeriesK589
ModelK 100 RT 84 (0504 ( 0505 )
Body typeK 100 RT 84 (0504
Catalog modelECE
Production date1985 / 01
Engine0514)
Transmission
Steering
CatalyzerNONE
    

13Back to top Go down    Re: How to get a cheap eBay Speedo to work on Thu Jan 19, 2017 5:52 pm

Jacod

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nods wrote:Very cool, thanks mate. I've no experience with 3D printing - do I download the plan and take somewhere that has a 3D printer?
I guess, yeah. I'd just google it to see who has one in your local area. I'm lucky enough to have access to one and get to use them on a daily basis. Perhaps you could try your local library  I've heard some are getting them in now.

    

14Back to top Go down    Re: How to get a cheap eBay Speedo to work on Tue Feb 28, 2017 4:56 am

dariok1

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How did U make the trim around the gauge with the battery, choke, etc symbols stamped ??

    

15Back to top Go down    Re: How to get a cheap eBay Speedo to work on Thu Mar 02, 2017 4:27 am

Jacod

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dariok1 wrote:How did U make the trim around the gauge with the battery, choke, etc symbols stamped ??
Aluminium, a Bandsaw, a Holesaw, and a dremel. 

Also, I should mention after riding the bike a bit the LED charge indicator light blew. I'm guessing the LED didn't like the charge coming back up from the alternator when the engine was at high revs. It was an easy fix though. I just put a new LED in the same way as last time, but this time I added second resistor that had a higher resistance the the accumulative total of the LED and the initial resistor. This means that when current is flowing from the battery to the charge indicator LED it lights up because the LED circuit has less resistance than the second short circuiting resistor. However, when the current is reversed flowing from the alternator; the LED, being a diode doesn't let the current flow through it so the current flows through the second resistor. If you don't know what I mean you need to google how an alternator works. 

Also that Google Sheets I linked in the initial post showing the polarity of the wires going to the speedo neglects to mention that the Oil Pressure light is also negatively polarised so you will need to wire it the same way as I suggested you wire the other negatively polarised lights. 

Hope this makes sense

    

16Back to top Go down    Further detail on Wed May 10, 2017 2:28 am

Jacod

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Further detail on how I finished wiring it up available here http://www.k100-forum.com/t12259-an-alternative-way-to-get-the-gear-position-indicator-to-work-on-an-aftermarket-speedo

    

17Back to top Go down    GREAT info on Tue Oct 17, 2017 2:32 pm

Gr-Racing

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Great info thanks,

I got it all wire but i still cant get the RPM to work for me i follow your wiring diagram i think but still nada
Can you give me a hand 

can you post a pic of how you did the capacitor and resistor

Thanks

    

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