Hour Meters Have Stopped Working on Both 4JH4AE Yanmar Displays

[impi]

Howzit Forum members ... I need some assistance. Both my Yanmar 4JH4AE electronic hourmeters have stopped displaying. I believe they operate from an impulse on the alternator ? (so someone tells me anyway).

What are the usual checks and how does one go about rectifying this issue ... accurate engine hours are very important to me

[colemj]

The tach works off the alternator, but the hour meters just run when 12V is present in the system. Check all the wires and connections to the control panel and to the D+ post on the alternator.

I am not familiar enough with Yanmar panels, but the Volvo digital hour meters go out all the time and there isn't really much to do to get them back.

I have installed inexpensive hour meters on the engines to keep track of hours.

Mark

[transmitterdan]

Originally Posted by impi

Howzit Forum members ... I need some assistance. Both my Yanmar 4JH4AE electronic hourmeters have stopped displaying. I believe they operate from an impulse on the alternator ? (so someone tells me anyway).

What are the usual checks and how does one go about rectifying this issue ... accurate engine hours are very important to me

I have never seen a single engine with two hour meters. Do you have 2 engines and 2 meters or 1 engine and 2 meters?

Dan

[S/V Antares]

The Tachs work off the same signal. Leaving the key on does not usually run the houres up unless there is a signal present. (That is what Yacht brokers say when the engines have too many hours) Most tach/hr combo units have simple stepper motors that drive a mechanical display (like a car speedo) or they have a digital display that works off the signal processor. Either work as long as there is a tach signal present. If the tachs work... the hour meter function is likely bad. Get a few cheap hour meters and put them inside somewhere out of the weather.

[impi]

I have two Yanmar engines with two displays ... both hour meters are down ... not at the same time ... one went down shortly before the other.

The suggestion / s to get a regular cheap hour meter is probably the way I will have to go but it would be nice to keep the original kit all in working order ... just cant figure out how this meter gets it's signal

[impi]

Originally Posted by colemj

The tach works off the alternator, but the hour meters just run when 12V is present in the system. Check all the wires and connections to the control panel and to the D+ post on the alternator.

I am not familiar enough with Yanmar panels, but the Volvo digital hour meters go out all the time and there isn't really much to do to get them back.

I have installed inexpensive hour meters on the engines to keep track of hours.

Mark

Thanks Mark ... from what I can see it seems all wiring is in tact ...

[transmitterdan]

Originally Posted by impi

I have two Yanmar engines with two displays ... both hour meters are down ... not at the same time ... one went down shortly before the other.

The suggestion / s to get a regular cheap hour meter is probably the way I will have to go but it would be nice to keep the original kit all in working order ... just cant figure out how this meter gets it's signal

Then it seems most likely that the meters are bad. Below is a simple test that may help you prove that.

I also have a Yanmar panel an d the hour meter is contained in the tachometer housing. I am pretty sure that the hour meter runs just off 12V but I'll check it next time I'm on the boat. If you can figure out which 2 wires are for the hour meter you can test it.

Think about where these meters are mounted. Are they in a location that is hot when the engine is running? Is there a lot of vibration on the panel where they are mounted? These are the 2 main contributors to hour meter failure. It might benefit the meters' lifetime to mount them in a cooler location with less vibration. Also, hour meters are generally not waterproof unless mounted in a special case.

Good luck,
Dan

[colemj]

Originally Posted by S/V Antares

The Tachs work off the same signal. Leaving the key on does not usually run the houres up unless there is a signal present. (That is what Yacht brokers say when the engines have too many hours) Most tach/hr combo units have simple stepper motors that drive a mechanical display (like a car speedo) or they have a digital display that works off the signal processor. Either work as long as there is a tach signal present. If the tachs work... the hour meter function is likely bad. Get a few cheap hour meters and put them inside somewhere out of the weather.

On our alternators, the tach and hour meter do not work off the same signal. The tach is taken from the W post, which is a pulsed signal from the stator. The hour meter is powered from the D+ post, which is a constant DC voltage.

So the tach can work just fine while the hour meter doesn't, and vice versa.

The alternator has to be working for both to operate, so the key switch isn't involved other than to start the engine.

Mark

[colemj]

Originally Posted by impi

Thanks Mark ... from what I can see it seems all wiring is in tact ...

The digital Volvo hour meters are notorious for not displaying. They still work fine and continue to count hours correctly, but they just do not display that information. Once in a while ours start to display again for a short period of time and I check their readings against the separate hour meters. The readings have continued to match exactly for the past 5 years.

Mark

[GordMay]

You can download your Service Manual
Here ➥ https://docs.google.com/leaf?id=0B59...thkey=CMrgofgD

[impi]

Originally Posted by GordMay

You can download your Service Manual
Here ➥ https://docs.google.com/leaf?id=0B59...thkey=CMrgofgD

Hi GordMay - went through the manual ... they refer to a number of Yanmar panel types (eg, BxB type, C type etc.) but do not display a drawing to show which type panel we have.

Any idea where I can get some picture or diagram to identify my type panel?

[GordMay]

Perhaps ➥ LAGOON Catamaran - construction, vente et location - constructeur catamaran de luxe, bateau de plaisance et de croisère

Or ➥ lagooncatowners : Lagoon Catamaran Owners Group

[Cheechako]

The hour meters I've had continue to run when the key is on. Nanni, Volvo, Perkins, and Yanmar. Maybe some of them are tied to an electronic interface...? That's the problem!! Get a basic , good hour meter that runs of the key switch. (NAPA Autoparts) Actuall, it's a good thing they do.... I can hear the clicking if I've forgotten to turn off the key!

[fairbank56]

Are these the analog tach displays with integral digital hour counter? If so, by "stopped displaying", do you mean they went blank? If so, I can offer assistance. Iv'e repaired a few with this common problem with VDO gauges. They might have the Yanmar label on them, but they are VDO. Even when on, they will not increase in count unless there is tach drive input.

The B type panel only has the tach gauge. The C type also has temp and oil press gauges.

Eric

[colemj]

Originally Posted by fairbank56

Are these the analog tach displays with integral digital hour counter? If so, by "stopped displaying", do you mean they went blank? If so, I can offer assistance. Iv'e repaired a few with this common problem with VDO gauges. They might have the Yanmar label on them, but they are VDO. Even when on, they will not increase in count unless there is tach drive input.

The B type panel only has the tach gauge. The C type also has temp and oil press gauges.

Eric

Hi Eric,

So what is the fix? Ours are blank, but still counting hours.

Mark