Bro 3.0 with cheap EBay speedo..

[BlacklightBeauty]

FYI - I gave up on this speedo after a few weeks... I had similar problems with N-2-3-4-5-5 gears as some others have stated. Nothing I did could make my speedo work with the BEP 3.0 (although after some research and info via @rbm I'll be checking the ground on my speedo cable)... Just sucked up the cost and ordered a mgadget mini speedo... Will post here if I have better luck given the price... Good luck to others going the cheap route!

[Ctrogstad]

After a few hours of searching, I found this document. Figured I’d share it just in case anyone else is dealing with the same issue.

 https://www.dropbox.com/s/g25vpdkat2az40j/speedometerInstructions.pdf?dl=0

Thanks for sharing the link. Have you determined the proper frequency setting for this unit?
Tks!

[t.penev89]

Hi Guys :)
First I  want to say that I've done this with my last k bike project  and I had no problems, just connected the speed and the rpm cable directly from the bep 3.0 to the speedometer and it started without any problems, however now on my second k bike project I have no working rpm and speedometer, everything else works gears indicators everything.
There are exactly the same speedometers but the interface and setting menus are different, also I bought them from different places.
So can someone give a correct solution, because now Ive tried with condensator and resistor and still not working...

[rbm]

RPM: You have to have the R-C integrator circuit attached to the RPM output of the BEP 3.0 to get it to work with this gauge.  This gauge expects the RPM signal to go negative relative to ground and the output of the BEP doesn't do that without help.

SPEEDO:  You'll probably need to borrow an oscilloscope to debug what is going on with the speedo circuit. Can you do that?  Right now, you don't have enough information to point to any failing component.  I wrote a user manual for this gauge.  Download it from my Google Drive:  https://drive.google.com/file/d/1IgZF3Qgx_Aa1mvcWAAjfVeTaBCb5WNkC/view?usp=sharing

[t.penev89]

Thank you very much for the quick response, yes my plan was also to check the speedo in a electronic workshop with oscilloscope or something like that to be shure that I'm using the correct input, because the user manual wasnt exactly matching the colors of the cables. I suspected that there will be problems when ive notice that...

My point was that, on my last K bike, I've used the same combination bep3 and this speedometer( on outside is the same) only the cables and the interface settings were different and it was easy job plug and ride 😁😁😁

Ill use your user manual wich Im very thankful for and ill see where is my mistake, Thank you again :) cheers

[t.penev89]

RPM: You have to have the R-C integrator circuit attached to the RPM output of the BEP 3.0 to get it to work with this gauge.  This gauge expects the RPM signal to go negative relative to ground and the output of the BEP doesn't do that without help.

SPEEDO:  You'll probably need to borrow an oscilloscope to debug what is going on with the speedo circuit. Can you do that?  Right now, you don't have enough information to point to any failing component.  I wrote a user manual for this gauge.  Download it from my Google Drive:  https://drive.google.com/file/d/1IgZF3Qgx_Aa1mvcWAAjfVeTaBCb5WNkC/view?usp=sharing

From the manual that you've made, finally I understood that the signal for RPM have to be negative...
The capacitor and resistor had made the signal lower but not oposite from positive to negative... can I take this negative signal from somewhere else from the coils maybe?
Ill try to make a RC connection and see what happens, hope it will work
Too much problems with this speedometer... 😒
There are different settings Y2 Y3 Y4 Y6 Y8,  do you have any idea which is the correct one, my logic and from the Chinese manual I understood that all are for 4 stroke engines only y1 y2 ... means the cylinders...

[rbm]

If you can send me a copy of your Chinese manual, I will attempt to interpret it and update my manual for you.

[t.penev89]

 [ Invalid Attachment ]  [ Invalid Attachment ] I found this on Internet and its like mine, the colors are the same like on my scheme, but my actual colors are different.
Also the guy from the store that I bought it gived me another schemes but still not matching the colors and the position on the back of the gauge.
20220314_170703.jpg (39.21 kB . 768x576 - viewed 379 times)
20220314_170712.jpg (40.29 kB . 768x576 - viewed 386 times)
-878259255-1793771366.jpg (49.25 kB . 768x549 - viewed 357 times)
20220316_194729.jpg (66.01 kB . 645x576 - viewed 325 times)
20220316_194704.jpg (59.99 kB . 665x576 - viewed 366 times) [ Invalid Attachment ]  [ Invalid Attachment ]

[t.penev89]

20220317_093027.jpg (89.37 kB . 768x576 - viewed 381 times)
20220317_093018.jpg (68.42 kB . 768x576 - viewed 383 times)And this is the one, as you can see different interface and different adjustments are made and it worked plug and play, first the rpms were not correct but after adjustments on the speedo it started normally. Also the speed was not correct, but when ive chose 7 magnets it was correct.

Maybe the electronic is different inside but it was easy job with the bep3

[t.penev89]

Now I've made this, like it was written in this topic, but still not any movement of the rpm dail...
20220317_101717.jpg (50.9 kB . 768x576 - viewed 355 times)

[rbm]

Do a quick test to confirm the gauge. Get a length of 18GA stranded wire and coil one end of it around one of the spark plug wires, 6 times in a tight coil, just like in the picture below.  Use electrical tape to secure it.  Connect the other end of the wire to the RPM input on the gauge.  Turn on the engine; does the tachometer work?

[t.penev89]

No 😒 no movement, I get 4.2V on blue cable, when I give some throttle goes 4.4v but no reaction from the speedometer, I tried the different settings Y1 Y2 Y4 but no effect

20220318_081555.jpg (85.2 kB . 768x576 - viewed 346 times)

[rbm]

Conclusion I draw is that your gauge is broken.  The RPM needle should respond to that signal on the Blue wire.  I'd contact the seller to see about a replacement.

[t.penev89]

I'm connecting it to Black/yellow wire, I've tested all the wiring so I can attach all my signals and 2 left, one for speed and one for rpm, non of them is giving mi response...
It's ffrom China, aliexpress, the replacement is going to be nightmare...
I'm ordering another one, hopefully it will work,
I'm very thankful for your support and advices, hopefully more people will see and solve their "mysteries"

[rbm]

Just to confirm, you are connecting the Blue wire to the Black/Red wire on your gauge going to Pin 17 of the big 20-pin connector.  Is that correct?

[t.penev89]

No, the black/ yellow on my gauge is on pin 8, which on the diagram is written as gear2, which is not correct.
This is upside 1-10

20220314_170703.jpg (39.21 kB . 768x576 - viewed 370 times)

This is lowside 11-20

20220314_170712.jpg (40.29 kB . 768x576 - viewed 349 times)

[rbm]

In Reply #32, you posted two colour coding charts. I chose the first chart, which appears to be wrong.  In the second chart, the RPM signal input is Black/Purple.  Is that the one you have connected the Blue wire to?

[t.penev89]

In Reply #32, you posted two colour coding charts. I chose the first chart, which appears to be wrong.  In the second chart, the RPM signal input is Black/Purple.  Is that the one you have connected the Blue wire to?

Yes, this is the correct chart, but stil there are differences with some of the colors, but I've tested all of them so I'm pretty shure that the black/ yellow cable is the rpm signal.

The seller sent me these other charts but totally different colors and cables positions...

Im waiting for other speedometer, after Iinstal the other one, I'll see what is the situation and Ill see if the speedo is defective or the problem is in me, I'm too dumb to wire 10 cables 🤪🤪🤪

Cheers for now, I'm stopping the spam of this thread, I'll only give my feedback after new speedometer comes and I'm hoping to be with different interface, familiar to me I hope 😀