Engine Hour (LCD) Meter Repair

[NorthStar]

[ Edit #2 by Moderator. See Post #68 for a replacement that so far is working. ]

[ Edit by Moderator. Please see Post #28, this fix will work for a short period but is only temporary and will fail again ]

I have finally had the time to troubleshoot and repair my Yanmar Tach-Hour meter. I believe what I found to be the cause of the chronic failures of this unit. I have attached what I discovered and did, with photos, as a PDF file to this email.

I believe this PDF content is as definitive a problem resolution as anything I have read on the subject over the last three years including emails on other sites that discuss cleaning the display ribbon cable connection at the circuit board. I did that too but in my case, this action alone did not resolve the display problem.

What I did goes well beyond what most of us will be able or willing to get involved with. So I agree that installing a Hobbs meter is still the best approach for most of us, I did that as well last season. The good news is that I believe all the display units could be repaired. I am very disappointed that Beneteau, Volvo, Yanmar or VDO North America has not stepped up to this simple manufacturing procedure and material problem as it seems to persist with this model.

North Star

 

[kloudie1]

Really good work, North Star. Congrats on a good fix.

 

[MichaelStacy]

You said "So I agree that installing a Hobbs meter is still the best approach for most of us"
What is the Hobbs meter? I have the same indeterminacy with my 2004 H33
Thanks - Michael

 

[NorthStar]

you can google "Hobbs hour meter" and see all about it better than I could tell you.
you can see a replacement tach/hour meter (VDO is the original mfg) here:
http://bayshoremarineengines.com/129271-91211yanmardigitaltachometerwithhourmeter.aspx

 

[syoun10]

Very interesting post, and good work! I have the same problem on my 2006 Hunter 33 with Yanmar 3YM30, but had assumed it was a grounding problem.

In my case, though, the tach is also unreliable. It sometimes goes up to full scale and often stays there until I restart the engine. This doesn't happen very often, but is still a pain. Do others have this problem too? Is it associated with the hour meter problem covered here, or an independent problem, do you think?

I also have the impression (but haven't proved it to myself) that the hour meter is not counting when the display disappears. Comments?

 

[NorthStar]

The problems with the LCD hour display are wide spread over many years in my six years of commentary observation. It has been reported the LCD display is failing even on replacement units. In every case I have seen, the hour accumulation continues normally, only the display is failing.
In your case of failing tach needle postion something additional is happening. The tach signal is corrupted some how. It is a good start to examine grounding as well as power supply. The tach needle is driven by a motor controled by electronics that respond to the tach signal applied to the unit. My signal comes from the alternator. You should investigate the quality of this signal in addtion to ground connections.
North Star

 

[sea_casper]

I have finally had the time to troubleshoot and repair my Yanmar Tach-Hour meter. I believe what I found to be the cause of the chronic failures of this unit. I have attached what I discovered and did, with photos, as a PDF file to this email.

North Star

Did you apply any protective coating to the back of the LCD to replace the failed one?

 

[NorthStar]

No I did not, it is a concern, because the stuff was put there originally for a reason.

 

[frenchguy]

Hi Northstar,

I will follow your procedure to try to fix my display on the Yanmar control panel.
Would you happen to have a wiring diagram for the tacho/display unit (+12V and ground)?
I want to test it on a bench back home.
Thanks

 

[Rich Stidger]

FWIW, I am on my third tach-hourmeter for my Volvo diesel. All three units failed with the same hour-meter problem of no display. I have in my possession the second and third unit, and coincidentally I am working on them right now to try the repair. Both of the units I have are made by VDO, but they are slightly different in construction. Neither of them have a disintegrating coating over the flat ribbon cable between the display and the circuit board. So the instructions given by Northstar don't seem to apply. I am about to power these up on my bench and see how they present today.

Attached is a wiring diagram for the VDO-branded unit. It is a near dead ringer for the Yanmar unit that is pictured in post #4 by Northstar. This wiring should apply to your Yanmar unit as well.

 

[GeorgeC1]

I have the same display problem that I would like to fix but I don't see the attached PDF file. How do I access this file?

 

[frenchguy]

FWIW, I am on my third tach-hourmeter for my Volvo diesel. All three units failed with the same hour-meter problem of no display. I have in my possession the second and third unit, and coincidentally I am working on them right now to try the repair. Both of the units I have are made by VDO, but they are slightly different in construction. Neither of them have a disintegrating coating over the flat ribbon cable between the display and the circuit board. So the instructions given by Northstar don't seem to apply. I am about to power these up on my bench and see how they present today.

Attached is a wiring diagram for the VDO-branded unit. It is a near dead ringer for the Yanmar unit that is pictured in post #4 by Northstar. This wiring should apply to your Yanmar unit as well.

Perfect, thank you. I'll post here the results of my findings.
Actually, looking at the wiring diagram, it does not match with the way my VOD is wired. See picture.
Pins 7 & 8 are not wired on the connector (these are the pins to connect to the actual tacho signal). And Pins 1 & 2 are wired (they are shown unused on the wiring diagram)
That will be interesting
Stephan

 

[Rich Stidger]

I have the same display problem that I would like to fix but I don't see the attached PDF file. How do I access this file?

The link to the pdf file is just above my signature.

 

[alexco38]

Switch to a Teleflex 7 years ago. No problem ever since, no fogging. Uses the Alternator as sensor.

Teleflex Marine Gauge Kits With Tach/Hourmeter

http://www.teleflexmarine.com/wp-content/uploads/2012/10/Teleflex-Marine-Expands-Gauge-Line.pdf

 

[Rich Stidger]

Final disposition: No joy. I was unable to observe or determine any visual fault with the LCD ribbon cable connections. I looked, probed, and pushed but I could not get any response on the display. Totally blank. It appears that I will either need to completely replace the LCD hour display or add a separate hourmeter.

Unfortunately, I don't have a nice spot to put the hourmeter, and I am getting tired of yearly attempts at repairing what I now have.

It's time for commissioning and launch, so I guess this issue will be put off again.

 

[GeorgeC1]

The link to the pdf file is just above my signature.

Thanks. The link does not show up when viewing on the mobile app.

 

[frenchguy]

Unfortunately, following the detailed instructions provided by Rich did not yield any results.
The LCD display is still dead, confirming the VDO unit is poorly built to begin with.

 

[Andrew Baer]

I have looked for a replacement VOD tach-hour meter but have been unable to locate one. Where did you purchase your replacement?

 

[Rich Stidger]

I bought one on eBay about 6-7 years ago. I've looked recently and also at the specific vendor that I bought from previously, but no joy.

 

[Rick486]

I have finally had the time to troubleshoot and repair my Yanmar Tach-Hour meter. I believe what I found to be the cause of the chronic failures of this unit. I have attached what I discovered and did, with photos, as a PDF file to this email.

I believe this PDF content is as definitive a problem resolution as anything I have read on the subject over the last three years including emails on other sites that discuss cleaning the display ribbon cable connection at the circuit board. I did that too but in my case, this action alone did not resolve the display problem.

What I did goes well beyond what most of us will be able or willing to get involved with. So I agree that installing a Hobbs meter is still the best approach for most of us, I did that as well last season. The good news is that I believe all the display units could be repaired. I am very disappointed that Beneteau, Volvo, Yanmar or VDO North America has not stepped up to this simple manufacturing procedure and material problem as it seems to persist with this model.

North Star

I accomplished this repair yesterday following your excellent pdf. It went smooth as silk and my hour meter now works like new.
Thanks again for your excellent work.