1983 Suzuki GS 1100 ESD Tach

[Guest]

My Tach doesn't register anything. I recently had a power surge that blew out all of my lightbulbs, ignitor, and the regulator rectifier was also found to be bad afterward although it was most likely the cause. I can't find parts for this motorcycle tach anywhere, so have been forced to take matters into my own hands.

With the bike ON but not running, I get 12V+ to the orange wire. I get no voltage across the white and orange wires.

With the bike ON and Running, I get a voltage across the orange and white wires that increases with RPM. The meter was set to the 20V scale, the meter determines AC or DC voltage.

I connected a AA 1.5V battery to the tach needle and it jumped to 4000 RPM's.

I have concluded that the problem lies in the circuit board between these sets of wires.

There is no visible damage to the board or the components on the board, although I did measure the resistance across the diode and found it to be .4 ohms, I then reversed the leads to find the same resistance measurement. I did not remove the diode from the board for testing. Does this mean the Diode could be bad?

The black chip in the middle has the letters ND SM014 11B11 stamped on it. If that is the culprit am I screwed? I tried googling that number but didn't find anything.

Please help me, I am trying to get the bike ready for a bike show at Road America in June.

Thanks

http://i464.photobucket.com/albums/rr10/zacharyalan09/IMG_0328.jpg

http://i464.photobucket.com/albums/rr10/zacharyalan09/IMG_0334.jpg

http://i464.photobucket.com/albums/rr10/zacharyalan09/IMG_0329.jpg

http://i464.photobucket.com/albums/rr10/zacharyalan09/IMG_0333.jpg

[mottyl]

"There is no visible damage to the board or the components on the board, although I did measure the resistance across the diode and found it to be .4 ohms, I then reversed the leads to find the same resistance measurement. I did not remove the diode from the board for testing. Does this mean the Diode could be bad?"

You really should remove the diode for testing or at least unsolder on end. If your meter has a diode check function you should have approx .6 of a volt in one direction and it should read open when you reverse the leads.

Chris

Not much help but at least you can find out if the diode is bad.

[Clone]

[IMG][/IMG]

You can replace everything on that board except the big black chip in the middle. If you take it to a fairly large electronic parts place they can hook you up with everything. I replaced the big green thing, the little blue thing and the two capacitors since all the resistors were ok. It works kinda, but this spring I took it apart again and cleaned out the old grease and put in a lighter lube. Hopefully it will work better.

[Nicholaschase29]

Did replacing those components help with your issue? What was the problem with yours that you had taken it apart? Do you know what the Green and Blue parts are? I can identify everything but those.

Do you know what the Brown wire is for? It connects to a yellow/black wire on the wiring harness. I thought it was a ground but did not get continuity between it and ground. Could this be my problem? Thanks.

[mottyl]

Either my eyes or my monitor are going. I don't see a large green thing. There are 4 caps at 11:00,4:00, 5:00 and one north of the ic which appears to be light blue?

Chris

[Nicholaschase29]

I was referring to the component sandwiched between three resistors on the right and a capacitor, resistor, and diode on the left on Clone's post. On my board that component is green. It sounds like you're saying that is a capacitor?

on another side note, if anyone has a wiring diagram for this part of the bike it would be awesome. I've found lots of 1983 GS 1100 diagrams, but not for this model, and none that diagram the internals of the instrument cluster.

[posplayr]

What someone with an ESD should do

is reconstruct a schematic from the art work.

Buzz the traces.

Maybe someone would offer some advice then.

Pos

[Nicholaschase29]

As requested here is the best I could do for a wiring diagram. Believe it or not it took me a while to make this from the circuit board. I'm also a lowly ME student so I haven't developed any of the finer EE arts yet. Hopefully it's adequate for whatever you need. I know it doesn't mean much without the IC DataSheet. Thanks for your help, and if you would like another rendition or think I may have made an error somewhere please let me know. Don't laugh too hard at my diagram.

[jadesystem]

I have the same bike with the same problem - I had to rebuild the entire
instrument cluster as everything was fried. I did buy the 33 and 22 Ohm
resistors and replaced them. I still have the spare tach PC board and other parts if interested. The 83 GS700 and the later GS750 share the same cluster, except the GS700/750 has a different LCD gear indicator and one less dummy light, yet the overall dimensions and circuitry is virtually the same.

I bought a used 700 cluster, and transfered most of the internal parts
to it. At least a few years of the 700/750 offering is a better chance to locate parts then the only 83 year 1100esd model.

The RR is definitely the culprit. And the isolation of the RR side panel with the grommets is crucial. Still good at 14.2VDC output @ 4k rpms with a
steady charging state.

One of my projects is to install those triple German VDO gauges found in those older VW GTIs, Jettas, Sciroccos, and Cabriolets. I can monitor
the charging state across the battery at all times as well as the oil pressure and oil temp. They look clean with the electronic sending units
a the bottom of the oil pan for oil temp, and at the dummy sending unit
"T"d behind the motor for the oil pressure.

Good luck on your resolution of the electronic tach.

[rustybronco]

My Tach doesn't register anything. I recently had a power surge that blew out all of my lightbulbs, ignitor, and the regulator rectifier was also found to be bad afterward although it was most likely the cause. I can't find parts for this motorcycle tach anywhere, so have been forced to take matters into my own hands.


The black chip in the middle has the letters ND SM014 11B11 stamped on it. If that is the culprit am I screwed?

not necessarily... you can always get a used tach from a different model and substitute the board or components.

this may help also.

http://www.thegsresources.com/_forum/showthread.php?t=66229&highlight=electronic+tach

***EDIT***
can you verify if 3v will read 8,000 rpm on the tach?

how about tach in a chip...

http://www.niksula.hut.fi/~mdobruck/siililand/mini/diy/alien/tacho/tacho-big.gif

http://www.national.com/an/AN/AN-162.pdf (see page 4 on how to use it)

***edit*** also see... http://www.siongboon.com/projects/da...0convertor.pdf

http://www.emesystems.com/pdfs/parts/LM2907.pdf

[Nicholaschase29]

not necessarily... you can always get a used tach from a different model and substitute the board or components.

this may help also.

http://www.thegsresources.com/_forum/showthread.php?t=66229&highlight=electronic+tach

***EDIT***
can you verify if 3v will read 8,000 rpm on the tach?

how about tach in a chip...

http://www.niksula.hut.fi/~mdobruck/siililand/mini/diy/alien/tacho/tacho-big.gif

http://www.national.com/an/AN/AN-162.pdf (see page 4 on how to use it)

The Tach in a chip option looks promising if I find the IC to be faulty. Will the Tach on a chip read double the frequency though since the 1 and 4 cylinders fire together? in the diagram they had the chip hooked up to a signal generator on the crank.

I'm trying to get in touch with an EE professor here who can hook this card up to a square wave voltage source so I can verify that it truly is the problem. To hook this up correctly is Orange +12V, Brown 0V and white is signal 0V?

One thing I'm currently concerned with is the brown wire. Is that supposed to be a ground? I traced it back to the wire harness and checked continuity from the frame ground to the wire but had none. Maybe I'll get lucky and all I have to do is fix that ground.

[rustybronco]

The Tach in a chip option looks promising if I find the IC to be faulty. Will the Tach on a chip read double the frequency though since the 1 and 4 cylinders fire together?

no, the 1&4 coils fire once per revolution.

I'm trying to get in touch with an EE professor here who can hook this card up to a square wave voltage source so I can verify that it truly is the problem. To hook this up correctly is Orange +12V, Brown 0V and white is signal 0V?

http://www.mtsac.edu/%7Ecliff/storag...-SD-ED-ESD.pdf (I have a hard time reading it!)

"wiring on the harness connector to the instrument panel"
(B/Y should be the tach input from the negative side of the coil.)
(O/G? should be +12V)
(can't read the last)

[Nicholaschase29]

no, the 1&4 coils fire once per revolution.

http://www.mtsac.edu/%7Ecliff/storag...-SD-ED-ESD.pdf (I have a hard time reading it!)

"wiring on the harness connector to the instrument panel"
(B/Y looks to be the tach input from the negative side of the coil.)
(O/G? should be +12V)
(

I've found that BassCliff has better resolution diagrams on his website, the PDF tends to get blurry when you blow it up. Which Diagram are you using? I think a lot of those, except the katana's, were the mechanical tach's. My 2&3 coil has a black and yellow ground/signal wire going to it. I guess that could be where the signal is coming from, I had just assumed it would take the signal off the number 1 cylinder but i guess it doesn't really matter. Not sure where any Orange/Green wires are though...

[rustybronco]

I've found that BassCliff has better resolution diagrams on his website, the PDF tends to get blurry when you blow it up. Which Diagram are you using?

http://members.dslextreme.com/users/bikecliff/

"GS1100 '80-'83 T,LT,EX,SZ,EZ,SD,ED,ESD (37MB)"
shows that B/y is the negative side of the coil.

[Nicholaschase29]

I'm sorry I was unclear in my previous post. Within the service manual which section are you looking at? which bike? I know the 700E has an electronic tach too. I downloaded a wiring diagram for it and a quick look over shows the B/Y wire coming from the coil. I'll look it over better after class.

Thanks again for all of your help guys.