Tach Isn't Working Right

[shavdog]

I noticed while out for a ride today my tach goes to 3 than sits there...won't go any higher when I accelerate....goes to zero when I shut the motor off and right back up to three when I restart....any suggestions for a troubleshoot appreciated...thanks...craig.....this is on a 2001 standard

[Chrisj CMA]

Is this an Interstate?

[shavdog]

this is a 2001 Standard.....I did take off the back of the tach and removed, sanded and cleaned the three wires....no change....tach goes to 3 and just sits there....back to 0 when I shut off....looking for other suggestions or help..thanks....the rear light comes on so I guess I would rule out a fuse issue as some others have had...

[shavdog]

This morning, in the dark I turned the ignition switch on and all the lights work and the background lights in the tach work as well as the idiot lights in the tach were ok...because the rear light works and the brake lights can I assume the ground is ok for the tach?

Heres my list to check

battery voltage

fuse

clean battery connections and frame ground

check the yellow wire in the headlight bucket

starter button clean contacts

anything else?.....can I buy a new tach from Honda?.....thanks for any help

I come up with a part number of 37255-MZO-A81...2001 1500cd....not sure if the model is correct...if anyone can verify my part number that would be helpful...thanks.

[Hook#3287]

Not ever having an issue with a tach, I've no experience with fixing one.

But, checking the wiring diagram, the Y/G (yellow/green) wire seems to be the one that powers the tach function from the ICM.

Seems the problem would be either the tack or the ICM.

If you know someone with a Valk C/CT, you could swap the tach to prove which.

You could get a used tach off e-bay just about any time.

Partzilla lists them new for $143.00.

The ICM is not available new, according to Partzilla.

[shavdog]

Thanks for commenting...I went back into the archives and see others have had the same problem I have today...in some cases they never post a conclusion so who knows what their repair was...anyway, this morning I pulled off the the headlamp bezel andchecked out the yellow wire, pulled it apart, sanded and back together...it never looked bad...checked the fuses, checked the battery ground all was ok...I'm with you either the tach or the icm...I may just order a new tach and hope for the best...apparently the tachs do fail...thanks again...I'll post my results..I ordered a new tach part number 37255-MZO-A81 for my 2001 standard....price was $143 plus $10 for a medial kit to put me over $149 and free shipping...I will let you know the results after installation...whats the best source for a used icm if I need one....

[Attic Rat]

When I installed the rostra  cruise control on my std I tied into that wire and did the same as you have described. I cut the cruise control ire out and it worked fine. Go figure. I tried into the same wire on my interstate when I installed the cruise on it and it did not affect it. So go figure.

[Firefighter]

Make sure your getting battery voltage and battery ground, same as when checked at the battery. Not just lighting a test light.

[shavdog]

Firefighter....if I get 12.5 at the battery are you saying I should get that at the tach?....and if that's right do you know which wire positive is at the tach....electrical is not my hipoint....the battery is only 3 months old

[Firefighter]

I had a problem with my battery ground once that affected my gauges. The battery ground wire attaches to the engine then the engine has a ground wire to the frame.  I have a Interstate so I am not familiar with your machine. Mine would do crazy things to the gauges and cause the engine to misfire. I ran a separate wire from the negative battery to the frame and my problems were gone. With a multi tester you should be able to determine which wire is positive and negative. If you have a given voltage at your battery you should have the same at your 12 volt supply to the tack. If you need wire color let us know and we can find out.

[shavdog]

Heres my new test...Valkyrie has been sitting for a couple of days...hooked up the multimeter and with the ignition off the reading was 12.50....at idle the reading was 14.17...does this bode well for my charging system mainly the altenator?....

[Valker]

Heres my new test...Valkyrie has been sitting for a couple of days...hooked up the multimeter and with the ignition off the reading was 12.50....at idle the reading was 14.17...does this bode well for my charging system mainly the altenator?....

Yes.

[Willow]

The tach on a Standard is mechanical, not electrical.  I'm not sure why some are encouraging chasing an electrical problem.

[shavdog]

Willow...I am going to order a new tach for my 2001 standard...does part number 37255-MZO-A81 sound right to you?...I don't want a restocking charge by ordering the wrong one...thanks to anyone that can confirm my part number...

[Willow]

Willow...I am going to order a new tach for my 2001 standard...does part number 37255-MZO-A81 sound right to you?...I don't want a restocking charge by ordering the wrong one...thanks to anyone that can confirm my part number...

That is the correct part number but don't jump too quickly.  The issue could be on either end of the tach cable.  It might also be something blocking the rotation of the tach needle that could be fixed on the current tach.

[Chrisj CMA]

The tach on a Standard is mechanical, not electrical.  I'm not sure why some are encouraging chasing an electrical problem.

Carl you may be confusing a MECHANICAL speedometer with a mechanical tach. A mechanical tach would have a cable like the speedometer instead of ELECTRICAL wiring. Just saying

[shavdog]

I don't know a whole lot but I think my tach is electric....when I took to cover over to reseat the wires there was no cable in there like a speedo cable....only about 5 wires ....

[Chrisj CMA]

I don't know a whole lot but I think my tach is electric....when I took to cover over to reseat the wires there was no cable in there like a speedo cable....only about 5 wires ....

Lol. It's electrical. I would still want to connect a donor tach to see if another one behaves differently before buying a new one

[shavdog]

That's a good idea but unsure where I would come up with that.....I live 200 miles north of mpls mn in the middle of nowhere...maybe someone would chime in if they are around here...thanks for your help...

[Bighead]

You could buy a used one cheaper on ebay.

[The emperor has no clothes]

That's a good idea but unsure where I would come up with that.....I live 200 miles north of mpls mn in the middle of nowhere...maybe someone would chime in if they are around here...thanks for your help...

Maybe try a WTB request in our classifieds.

[Willow]

The tach on a Standard is mechanical, not electrical.  I'm not sure why some are encouraging chasing an electrical problem.

Carl you may be confusing a MECHANICAL speedometer with a mechanical tach. A mechanical tach would have a cable like the speedometer instead of ELECTRICAL wiring. Just saying

You're quite correct.  I was saying tach but my mind was thinking speedometer.   

[Gideon]

I noticed while out for a ride today my tach goes to 3 than sits there...won't go any higher when I accelerate....goes to zero when I shut the motor off and right back up to three when I restart....any suggestions for a troubleshoot appreciated...thanks...craig.....this is on a 2001 standard

Check your ignition switch. The ignition controls three different circuits: IG1, IG2,and FAN. The trouble may be with IG2 circuit. The IG2 controls the tachometer, tail lights and head light.

Just a thought.

[shavdog]

My tail light, brake light and headlight works fine....would that circuit with the tach on it be deemed ok if those other functions work?


so far I have done this

taken the tach apart and sanded and reconnected all of the wires

rechecked the battery ground...the battery is 3 months old....with my multimeter with the engine off it registers 12.50 and 14.17 at idle..

I sanded and reconnected the yellow wire inside the headlight


I don't know the history of these Valkyries but this is my 4th one....I did a search on here and it looks like the tachs can and do fail occasionally....this bike has spent its history away from salt conditions and there is no corrosion on this bike...it has 48k on it..Right up front my skill level is somewhat limited so it's alittle bit of a crapshoot  for me to fix this...based on what I just said is it most likely the tach or maybe the icm?...I'll take the tach apart again and try and measure the voltage at the tach...I'll report in with that number....thanks for helping me out...

I am alittle hesitant to buy a used one on ebay with the prices they want....a new one costs $143..
and a used ICM is about $80 if I strike out....and no guarantees either of those are the fix...

[shavdog]

Heres my test for today...I took the cover off the tach for another test...I used my mutimeter and here are my results with the ignition key turned on....no motor....the light in the tach anddummy lights all look normal

Black/brown wire.......11.6

black/brown wire(second one).......11.6

green......06

yellow/green.......06

I also disconnected the three prong plug and each male end(in the unit) read 11.50....when I put the multi meter on the plug itself, I got no reading...didn't know if that was right or not...does anyone know how to check the icm to make sure there is flow from the icm to the tach?


I hope someone can interpret this.it looks like power is getting to the tach.....thanks again...craig

[gordonv]

1st thing, add your location to your profile. A neighbour might just call up and help you out.

2ndly, do you have the service manual? Get a PDF copy from Valkyrie Norway.
http://valkyrienorway.com/download.html
I think there should be a section on How-to trace your problem.

I would also suggest before buying anything, to ask for any locals who would be willing to swap out their tach to see if it works in your bike.

[Detn8er]

You could also do what I do........Just ride it and don't ever for any reason look at the tachometer. The bike does and will run for ever without it......How do I know this? I bought my Valk new....Tach hasn't worked since it had less than 3000 miles on it. Now at 125000 runs better than when new.
Seriously while out riding I noticed the tach bouncing when at a stop light...from that point on it will go up to around 3000rpm and just sit there until it is turned of then drop to zero. Just not something that's a big deal to me. never needed or cared what rpm I was running at any given time. Course your needs may vary from mine but it not working is not a major thing....  Oh and I did many of the things you are trying now with the same results.....Nuttin.

[The emperor has no clothes]

You could also do what I do........Just ride it and don't ever for any reason look at the tachometer. The bike does and will run for ever without it......How do I know this? I bought my Valk new....Tach hasn't worked since it had less than 3000 miles on it. Now at 125000 runs better than when new.
Seriously while out riding I noticed the tach bouncing when at a stop light...from that point on it will go up to around 3000rpm and just sit there until it is turned of then drop to zero. Just not something that's a big deal to me. never needed or cared what rpm I was running at any given time. Course your needs may vary from mine but it not working is not a major thing....  Oh and I did many of the things you are trying now with the same results.....Nuttin.

especially with having the limiter. You know when you over rev it.

[shavdog]

WT.....my tach works....I have no answer to why it works.....the last thing I did was take the overflow tank off and look at the icm...I stared it down pretty good...I didn't take it apart but did pull and push around on it....exactly how does that come out of there...it's encased in a rubber casing on two side pins..does that whole thing just pull off of the pins then you can separate the icm?....last night I did sand on the three pin connector and retightened the four screws....whatever I did, changed something and now I know that my tach isn't totally shot....I'll just move on and see how it goes....thanks again for everyones response ....craig