• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

No functional tach - 85 GS700E

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Guest
Ive read around on here about other models with similar electronic tachs and also read one talking about replacing components on the circuit board. But what I need to do first is figure out if the problem is in the wiring. I cant find the info on any wiring diagrams as far as what color wires go to the tach and what wires are for power, signal, and ground (i assume ground is black with a white tracer like the rest of the bike)

I want to make sure Im getting power and everything to the tach before I start soldering on the circuit board.

Thanks guys for any info you can provide.
 
Hi,

On my little website there is a GS700 Supplemental Manual containing a wiring diagram. It may help.


Thank you for your indulgence,

BassCliff
 
Thats what Ive been using but I cant see that it shows the wire colors so that I may test the tach and see if it is getting power/signal/ground to the circuit board.
 
Last edited:
The wires should be black/white ground; orange or orange/green power; and black/yellow single.
To test wires use voltmeter or test light. Turn on key, don?t start.
Test black/white to battery hot +, got voltage good.
Test orange to battery ground -, got voltage good.
Test black/yellow to battery ground -, got voltage step 1 good.
Turn off key and unplug orange from coils.
Unplug ignitor.
Turn on key and test black/yellow to ground -, got no voltage step 2 good.
Turn off key and plug coils and ignitor back in. If all test good your wiring is fine.
If I got the wiring diagram right the wire colors should be the same. If not the test will be (ground, power and single).
 
Thank you very much! One more thing to add to my list of things to do tomorrow :D
 
well everything checks out according to the list above so I guess its time to open up the cluster and check things out
 
Last edited:
anybody have any tips on how to get into the board? do I need to take out the two small screws on either side of the speedo and tach needles?

Forgive me but I just want to be sure before I mess it all up :oops:
 
I got it taken apart. And I tested the circuit board by touching a AA battery to the + and - wires on the board itself and I got 7000 RMP on the tach, I dont really know what that means though. Im trying to read through this other thread about it but im a little lost.

But I tested the resistance on all of the resistors and only two of them read anything, and they are correct. Do I need to disconnect them to test? I cant remember but I guess Ill start with replacing the resistors, I know I can get those at radio shack tomorrow.
 
Last edited:
The tach on my buddy's 700 is dead as well, or mostly dead anyway.

I'll be following this thread with keen interest, as I'm hoping to help him repair/restore over the longgggg winter.
 
I got it taken apart. And I tested the circuit board by touching a AA battery to the + and - wires on the board itself and I got 7000 RMP on the tach, I dont really know what that means though. Im trying to read through this other thread about it but im a little lost.

But I tested the resistance on all of the resistors and only two of them read anything, and they are correct. Do I need to disconnect them to test? I cant remember but I guess Ill start with replacing the resistors, I know I can get those at radio shack tomorrow.

You have proven that the meter itself is working with your battery test.
It means that it is the board that is probably faulty or any wiring into or out of it.

Does your board use transistors or does it have a small chip on board (mostly on later tacho's)?
I would suspect any transistor but will first change all the electrolytic capacitors regardless as they tend to "dry' out due to age. Another suspect will be any diodes especially any on the input or power side. Resistors showing burning are also suspect, but I would test these last, write down the colours first in case a scab pops off.

It would be much easier if you try to draw out the schematic as the board should have a low component count and not be too complex, then the electronic boffins will be able to guide you much easier.

Here is a copy of a BMW tacho for your information:
attachment.php
 
I have a glassless cluster that has a functional tach you could swap into yours. If yours ends up being faulty.
 
Back
Top