I just removed the speedo from the bike to try solving an annoying problem.
I remember seeing a week or so ago what was the answer to my problem but don't remember where (too much to read on the forum - I am like my computer.... the processor is up to date but the memory is full...)
Here is the problem: sometimes, the speedo won't work and after just a gentle tap on it, it will work until the next trip.
If I remember correctly, it was about a 3 pins connection. I open the speedo and only found a 4 pins connection.
Is that the connection?



Today I also received the LEDs to install in stead of the bulbs.
First, the base of the LED is a tiny bit to big an will have to be trim down Maybe 1/64").
Second, as a LED will not work if you reverse the polarity, I will have to track the polarity on the circuit.



CF

Could be it was this post that was lost during the hard disk error?:
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Re: Speedometer, Tachometer, and Cogs near breaks
by Inge K. on Sun Feb 05, 2012 1:29 pm

.Other known weak connector points in speedometer signal circuit is:

At the bottom of the connector pins at the multiplug connection on the rearside of the instruments.
The pins is pressed/clinched to the plastic frame with the conductive film between.
At this spot a galvanic reaction occurs, due to the different materials.
The reaction got good help to develop from condensation problems in the instruments.
This area get less heat and air to dry up again, with good help from the rubber gasket
to keep the moisture in place.

Another known cause for speedo failure is the three pin connector at the end of the conductive
film which is connected at the top/rear of the speedo.
It`s a piece of rubberfoam on the rearside of this connector, to add a slight pressure to the connector.

Inge K.
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From the Flying Brick Forum:



Inge K.

Thanks for the quick answer Inge K.

would it be this one?
This is the only 3 pins connector that I can find on the speedo part. as the bike is stored for the winter, I would like to be able to pinpoint the problem before I put it together for this spring.

The day that spring will come, I won't have any time to work on the bike. It will be riding only!
Now, the bike is in the shed and it's too cold to work on it.
What a life!!!

Inge K,

You updated your post and I didn't see it. This is exactly what I was thinking.

Thanks a lot.

Bert

That`s the one, copy and save...to your recently purchased hard disk.

Inge K.

Re: polarity of LEDs...they usually have a "flat" on the base of the LED. This is the cathode, ie, -ve connection. Also, the LED behaves like a normal diode, with a multimeter on Ohms, has a high resistance with the test leads one way, and a lowish resistance with the test leads reversed. With modern multimeters, the red test lead is +ve in the Ohms mode. So when the lowish resistance is indicated, the red lead lead is on the anode, and the black lead is on the cathode, so when placed in service, the anode is connected to the +ve supply.

Rickmeister.

I'm surprised at you CF - it is your forum after all

Check this link:

Speedo Dying ?

krambo wrote:I'm surprised at you CF - it is your forum after all

Who's forum?
Without an international community of great guys like you, this forum would be dead for long time.
I purposely decided to minimize my time on this forum to see if people would assume their role as active members.
I wasn't surprised to see the success.
I am asking for help... Yes, because after all nobody has the supreme knowledge and it's legitimate to use the experience of others

Now, it leaves me a bit of free time and I enrolled in a mentor ship program to help high school students to develop mechanical and engineering aptitudes. The goal is to achieve the design and construction of an ROV (Remotely Operated underwater Vehicle). These students may be your next mechanic or the designers of your next bike.
Believe me it's not an easy task as some of them never held a wrench before. At one point, we all started to learn, and I am eager to pass my knowledge to the young generation.
I believe that most of us in this forum stand for the same principles.

CF

Ulrich_Grabau wrote:Re: polarity of LEDs...they usually have a "flat" on the base of the LED. This is the cathode, ie, -ve connection. Also, the LED behaves like a normal diode, with a multimeter on Ohms, has a high resistance with the test leads one way, and a lowish resistance with the test leads reversed. With modern multimeters, the red test lead is +ve in the Ohms mode. So when the lowish resistance is indicated, the red lead lead is on the anode, and the black lead is on the cathode, so when placed in service, the anode is connected to the +ve supply.

Rickmeister.

Thanks Rickmeister,

The problem is not to find the polarity of the LEDs, but to trace the speedo circuit to find where positive and negative are. (an incandescent bub can go both ways. Not the LEDs)
This is a difficult task when the bike is shivering in the shed and the speedo is comfortably resting in your heated workshop.
The link between both is 100ft, snow on the ground and 40 degrees apart. With no battery on the bike, this makes it a difficult task.

CF

The polarity of connections in the speedo are consistent from what I remember. I installed Duck's LED kit by following his instructions. My recollection was that the orientation of the LEDs was all +ve facing inside (or maybe all -ve facing inside). I searched for but was not able to find a copy of his instructions to make sure. This doesn't help you a great deal, CF, but maybe another member who has bought and installed the LED kit from Flying Duck can pipe in. Otherwise, I'll continue to search my papers for his instructions and post here if I am successful.

GitH did earlier post pictures of Drake Smith`s instructions in this thread.

Inge K.

Thanks for remembering that, Inge. I recall seeing that image but lost which thread it was posted in.

Hey CF My next bike was built before they were born. Sounds like a nice thing to be doing though. Keith

Lvog57 was reading my post and sent me this clear picture...

Thanks Bro.

thanks lvog

My speedometer guts definitely don't even look 10% as nice as Lvog57's do...

FreebasserSF wrote:My speedometer guts definitely don't even look 10% as nice as Lvog57's do...

Just print off the photo, trim around the edges and glue it over yours...you too can a speedo that looks good.

Even with the printed picture I will still have the problems of non-moving speedo and tach needles. At least they will be pristine non-moving needles and I won't be able to see the ABS and overheat light which stay on. Problem solved.