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Interment Dead Tach

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Old 06-13-2010, 07:56 AM
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Interment Dead Tach

1998, so old style gages.

The Tach will intermittently stop working, some times for a few moments, some times for the whole ride.

Yesterday, it did not work from start up.. left for a 6 hour ride, several starts and stops, dinner, gas coffee, etc etc... tach was dead the whole day until just before last gas stop on the way home.. Did not hit a bump, did not do anything different,, just riding along and the needle swung in to action.. Worked the rest of the way home (40 miles)

Not sure if it will work this morning, but chances are it will.

Another clue.. or data point.. It has done this several times before,,, and I though it was keyed to washing the bike or riding it in the rain......

If I understand the wiring diagram and service manual, the signal is generated from the CDI... as CDI's are a potted, non switching analog deal,, I don't think it's even possible for it to be part of the issue... Though next time it stops working when I have the bike at home I will check for signal... and rule that out.

So wiring? An open or bad connection?

Something inside the dash, fracture on the PC board? wiring connection?

I did some searches here and really did not find much as systemic problem pointing to any one failure point. Anyone seen this and found the issue?

Last edited by E.Marquez; 06-13-2010 at 08:05 AM.
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Old 06-13-2010, 08:57 AM
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Try disconnecting the black coupler at the back of the block, near the swingarm, and firmly replug. My speedo was intermittant, and this coupler was soft set, doesn't happen anymore.

Mark

Last edited by markm70; 06-13-2010 at 08:57 AM. Reason: mistake
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Old 06-13-2010, 11:35 AM
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I had a tach on a 99' VTR that was intermittent which finally died. Opened it up to find a burnt resistor. Found the correct resistor at Fry's Electronics soldered it in and now it works great!
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Old 06-13-2010, 11:56 AM
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Yea mine shuts off when I wash it. Untill the part dries out it stays like that. Mine is not the Tach it is the speedo
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Old 06-13-2010, 12:01 PM
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Originally Posted by markm70
Try disconnecting the black coupler at the back of the block, near the swingarm, and firmly replug. My speedo was intermittant, and this coupler was soft set, doesn't happen anymore.

Mark
clean and then use dilectic grease on the connector too
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Old 06-13-2010, 01:10 PM
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Originally Posted by markm70
Try disconnecting the black coupler at the back of the block, near the swingarm, and firmly replug. My speedo was intermittant, and this coupler was soft set, doesn't happen anymore.

Mark
I will double check the signal generator and the connenction.. But my understanding is that it is just for the speedo... The Tach signal is coming from the CDI.. Need to go look at the wiring diagram again.
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Old 06-13-2010, 01:14 PM
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Originally Posted by inderocker
I had a tach on a 99' VTR that was intermittent which finally died. Opened it up to find a burnt resistor. Found the correct resistor at Fry's Electronics soldered it in and now it works great!
Ya, thats what I was thinking as well.. On the DRZ's I own, follow and work on.. we have an issue with the OEM dash and one solider connection to the board...

Removing and checking the dash will be my first check this evening... Been playing with the new lathe and mill all day making chips... while watching my buy put bushings and seals in his forks.. Now it's my turn at the bike lift...
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Old 06-18-2010, 06:01 AM
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Well Tach worked for two days, then died again, So

All connectors removed, checked, cleaned with elec contact cleaner, greased, replaced. The wire attachment on the back of the gage pod, removed, terminals and screws cleaned, greased, replaced.. Tach worked for 140 miles yesterday,, then died for 40, started working again for the last 50....
Elec components do not fail, burn,etc etc then fix themselves,,, So I'm thinking is has to be a wiring issue.

The question is where....??

I'm tempted to isolate the signal wire from the CDI, run a new one all the way to the tach.. If that fixes it, I'll leave it til I have an inclination to strip the bike to the frame, take the wiring harness apart and replace that wire.

Any other ideas?.. I wish the darn thing would fault when it's in the garage so I can check signal at the distant end of the harness.... Would be so much easier of I could isolate the issue to at least that connector backward, or forward to the gage itself.
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Old 06-18-2010, 12:40 PM
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Yup, if it's coming back to life you most likely have a bad connection. The service manual has some diagnostic steps starting on page 19-12.
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