Dead Speedo/Odometer

[toodie]

I know there are plenty of threads already on the topic. No speedo or odometer readings. Tach still in operation. I assume the power has been disrupted somewhere. My question is that the speedo needle has swept all the way to right side...is this an indication that somehthing more is wrong than just loss of power?

 

[BATMAN2696]

Mine has done the same, At first it would start dropping off speed while riding, Then one day while cruizing along at the same speed it started climbing slowly for about 10min untill it was pegged. Now it stays pegged like the one in the pic until I start the bike then it will back off to about 50mph. The Odometer has not come on in months. I took it apart and checked all the wiring but nothing seemed loose or helped.

 

[bruce]

need to take speedo totally apart, On back you will find plastic holder where wires come out, if you remove I think you will find one or more wires have come un-soldered , you will have to totally disassemable and re-solder wires, It's does not work you have nothing to lose. there are how to's on this site. I have had things like this two different time and both times it was awire broken at solder spot, but you really have to look. I see you live in baltimore, If you want to take a ride I would be glad to help you. or just take off speedo and bring up.

 

[toodie]

Bruce - thanks for the offer! I can certainly tear it down but from there not so sure but will give it a shot Like you said don't have anything to lose

Keith - I got nothing what you see is what I have regardless of running or not.

 

[toodie]

Is it neccesary to disconnect the battery to pull the speedo?

thanks

 

[Oscar Maldonado]

Is it neccesary to disconnect the battery to pull the speedo?

thanks

It's always a good idea to disconnect the battery for anything done you bike but not nessessary for that being it's a quick connect connection. I've don't it many times with no problems.

 

[toodie]

cool thanks oscar. with the 08 it's a little more involved to pull the seat that is why I asked.

 

[toodie]

well i can see the issue now. both the green and red wires are broke off at the circuit board. problem now is the unit seams like it is sealed no way to open it up. have been searching BDM but have yet to find anything related to actually getting to the circuit board to repair broken wire(s)

 

[bruce]

it is what I said, use a small screw driver on ring around glass , you will have to bent it out around egdes. when you take apart be careful to watch how it comes apart. after you fix wires put back together. help call me it will me easier for me to tell you on phone 717-382-9983 Bruce

 

[toodie]

Bruce thanks for the tip...was able to get it all apart.. I found Ray's how to which is a big help as well. Now I started with 2 broken solder joints but in disassembly I now have all 3 broke. How do I determine which joint is which. I believe the black/ground was tied to the joint labeled E4. Looks like E1, E2 & E4 are used. I have some soldering tools that have never been used but would like to give it a try before shelling out hundreds of $$ for a new speedo just because of some broken wires.

Again this forum is awesome and thanks for your help

 

[bruce]

do you have shop manual, wiring diag. should show you which goes were.

 

[toodie]

The manual shows Pin locations on the backbone harness connector but nothing that I can see that indicates the connection on the circuit board itself.
Red = B31
Green = B50
Black = B8

 

[toodie]

Anyone have a suggestion on how to determine which wire goes where? I contacted Autometer they were no help. It's late but I believe there would be a total of 6 permutations?? I would assume however trying to use process of elimination using live current would damage the circuit board if I don't get the right combination on the first try

 

[erldawg]

Anyone have a suggestion on how to determine which wire goes where? I contacted Autometer they were no help. It's late but I believe there would be a total of 6 permutations?? I would assume however trying to use process of elimination using live current would damage the circuit board if I don't get the right combination on the first try

Take a picture of both sides of the board and post it up so I can look at it. There should be some sort of markings on it...

 

[toodie]

I believe the ground/black was tied to E4 but not 100% sure

 

[BigDogBro1]

For what it's worth.

MAKE SURE YOU ARE ESD GROUNDED! or you can damage the circutry from static charges just by handling the PCB assembly.

Okay, now that that's been said...

VR1 is a voltage regulator (National Semiconductor) and drops the incoming 12v to 9 volts for the speedo circuitry. Two of the solder points should connect to pins on the VR1. One for 12v power input and the other for GROUND.

If you web search the part# (LM2940S-9.0? I can't make it out well enough) on the VR1 you could find a component pinout diagram that will tell you which pins are for power and ground wires. You may need to trace around with an ohm meter.

I think this is it, but check it carefully to be SURE.
http://www.futurlec.com/Linear/LM2940CT-5.shtml

Component PDF file PAGE 2..........TO-263 case style shows the pinout.
Referencing your PCB picture above.....the E3 label is near pin 1 of the regulator (1-INPUT)....(2-MIDDLE PIN is GROUND)....(3-OUTPUT).

By process of elimination, once you determine the power and ground connections you can then determine the final signal wire connection.

Hope this helps you out.
Cheers

 

[toodie]

Bigdog Bro1 :2thumbs: some awesome info there thanks so much gives me plenty to start with....
Couple of questions:

1. ESD GROUNDED

• 
  what do I need to do to accomplish this? What about transporting/traveling with the PCB?

2. I have an ohmmeter but do not know how to use yet

• 
  Now how do I determine which pin ties to which solder point? Is it as simple as getting a specific reading by placing the test leads from the VR's Pin 1 to each of the sodler point?

 

[erldawg]

Bigdog Bro1 :2thumbs: some awesome info there thanks so much gives me plenty to start with....
Couple of questions:

1. ESD GROUNDED

• 
  what do I need to do to accomplish this? What about transporting/traveling with the PCB?

2. I have an ohmmeter but do not know how to use yet

• 
  Now how do I determine which pin ties to which solder point? Is it as simple as getting a specific reading by placing the test leads from the VR's Pin 1 to each of the sodler point?

1) You know when you walk across the carpet and touch a door handle or another person and you get a shock? That is ESD discharge which can damage the components on the board. So you need to ground yourself before touching the board. To transport it you should place it in an ESD safe bag, which you probably do not have unless you have some computer hardware laying around that may be inside a ESD bag. Like whn you buy a new sound card or ethernet card etc:

2) The pin closest to the recessed circle on VR1 and labeled "1" should be the input pin. The center pin should be ground. Take you ohm meter set on lowest ohm scale and touch Pin 1 of VR1 (red lead) and touch E2, E1, E4 (black lead) when the meter reads 0 VR1 is connected to that pin, then do the same with the center pin of VR1. My guess from looking at the board Pin 1 of VR1 connects to E2 this is where your power wire from the harness will go. Need to refer to the schematic to see what color from the harness. Then your ground wire from the harness will connect to the other Ex: E1 or E4. Now this leaves only one wire left from the harness and you will connect it to the remaining pin whichever it is E1 or E4.....

You will need a soldering iron, solder sucker, flux and solder.

 

[bruce]

toodie have you got it fixed yet, if not and you want to take a ride here. I am sure I could help. I live in fawn grove, which is north of belair md.

 

[toodie]

toodie have you got it fixed yet, if not and you want to take a ride here. I am sure I could help. I live in fawn grove, which is north of belair md.

Bruce - thanks for the offer :2thumbs: I think Bro1 & Earl have provided enough information to make me dangerous like you said I don't have anything to lose.. Will have to get up your way for a ride once some nice weather comes around

Bro1 & Earl - thanks you guys rock!