Tachometer Issue...Maybe

[f-Stop]

So...twice this winter I've started up Hildr the Valkyrie -- '98 Standard -- and the tach went to 3000 rpm upon starting and stuck there for about five miles.  Then worked perfect the rest of the day...re-starts and all.  

Both instances the temps were in the mid-40's (˚F) inside the garage, all the indicator lights came on when the key turned on, the bike started at the first crank and then ran perfectly well (even while the tach only read 3000 rpm).

But...this condition doesn't happen every time it's cold...it's happened only twice.

I assume this is temperature related, but might not know different until this spring or summer.

I have not checked the voltage from the ICM yet, but I expect there won't be any voltage anomalies unless the tach is in it's "stuck" position.  Recreating this condition could be difficult.  

I have checked the connector at the ICM (which seemed fine), but have not checked the connector inside the headlight housing.

Anyway, has anyone else experienced a similar event?  If so, was it a prelude to an ICM failure or maybe a Tachometer failure?  Or was it just an iffy connector inside the headlight housing?

Pre-thanks for all your insightful and knowledgeable responses!

 

[Valker]

Strange as this sounds, check your taillight. If the bulb has issues, the tach won’t work. Just another thing it MIGHT be.

[WintrSol]

Have you tried 'percussive maintenance'? IOW, tapping the meter? It could just be sticking because of the cold. Or, it could be the connectors could need cleaning, and this is your first warning.

[f-Stop]

Hey Valker, checking the tail light is not strange at all.  The Tachometer, tail light, indicator lights and the neutral light are all on the same 10A fuse.  One thing I did not do was to check the tail light while the tach was stuck at 3000, but I do know that the neutral light worked while stuck and the indicator lights came on when the key was turned to the on position.  When this sticking thing happened Christmas Eve (which was the second sticking time) my son and I were about to take a jaunt out to Luckenbach.  My son did not mention anything about the brake light not working.  So, I just now asked him and he did not notice the light not working as we headed out.

Yeah, WintrSol...tapping on the Tachometer was the very first technique used...it came naturally to me.  I figure that if there were some sort of crud on the little needle shaft, the needle would end up sticking in different places.  As stated, the Tach worked perfectly fine after about five miles.  Nevertheless, I do suspect an iffy connection in the Headlight housing.

[WintrSol]

Next question: you said the indicator lights all worked, but did you notice if the light that illuminates the dial was on? It uses the same ground as the tach.

[f-Stop]

I did not notice if the dial light was working while "stuck" as it has been daylight when it has happened.  That light was working fine last night when I rode home from my warehouse...so was everything else.

Also, just to clarify, by "indicator lights" I'm talking about the oil light and the kickstand light...I'm assuming the temperature light is working OK.

[WintrSol]

I did not notice if the dial light was working while "stuck" as it has been daylight when it has happened.  That light was working fine last night when I rode home from my warehouse...so was everything else.

Also, just to clarify, by "indicator lights" I'm talking about the oil light and the kickstand light...I'm assuming the temperature light is working OK.

Those indicators share + power with the tach and dial light, but get their grounds from the sensors. That's why I went for the ground, common to the tach and dial light, but not the indicators, which enter though the same connector as the others. It can be hard to see that light in daylight, so maybe just open and clean that connector, and keep an eye on it. If it happens again, it is likely the meter; if you forget about it, it was the connector.

[f-Stop]

Thanks WintrSol...

I'm hoping for a dirty or bad connector (and suspect as much).  Plan to knock off work a bit early tomorrow, then get into the headlight to perform the tach/ICM voltage check procedure as per the Honda shop manual.  I'll also check all the connectors in the headlight housing as well as the tach itself.

 

[f-Stop]

So...got into the headlight housing and started to check all the connectors.  Found this immediately...

https://drive.google.com/file/d/1ynBazeXZPIreC9jmBSYv3TiySM8_I2Tk/view?usp=sharing

...looks like a possible grounding issue to me.