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peterp · 07-06-2015, 06:15

I always log my engine hours on shutdown, recently the display was blank on one engine then a couple of hours later on arrival at our home marina the other display failed, the tacho's are working fine as is everything else, I checked the wires that go into the back of the tacho there is simply a removable plug with about four wires connected, I removed the plug checking for any loose wires or corrosion etc. all seems good, also noted that when I pushed the plug back in the light inside the tacho came back on so I know power is OK although I guess the hour meter could fail even though the light is on. Here is the odd bit the following week after a short run the hour meter came good all by itself with the correct hours displayed, I was pleased that whilst the display had failed the hours are being correctly accumulated. This weekend both hour meters have failed again. In summary I feel it is a connection problem but I think the connection is OK at the tacho end, I am unsure where the hours information comes from, my engines are 40 HP Yanmar 3JH5E about 230 hours total time Lagoon 400 about 4.5 years old, I did call Yanmar here in Australia they advised it would be rare for my problem. I would be most appreciative if anyone can help, or have experienced the same problem. Thanks in advance.
Regards Peter

colemj · 07-06-2015, 06:35

Yep, that is a very common problem for the VDO tachs with the LCD hour meter display. The accumulated hours continue to be counted, but you can't see them.

If you search the forum, you will find a "fix" posted that requires taking the entire thing apart and cleaning a ribbon cable connection. This is a very fiddly thing to do and may not work (it did not solve the problem on one of ours, and solved it for the other, but only for a few months). It is also very easy to break it entirely, so make sure you are comfortable doing this type of work.

If you buy a new tach, you won't have the old accumulated hours and it too will fail in a few years.

My solution was to just install an independent hour meter.

Mark

**GordMay** · 07-06-2015, 06:52

From SailboatOwners

Muckle Flugga · 07-06-2015, 07:10

One of the reasons newer is not necessarily better. Mechanical dial hourcounters don't do this. I actually don't understand the benefit of having one with an LCD readout?

colemj · 07-06-2015, 07:13

Quote:

Originally Posted by Muckle Flugga

One of the reasons newer is not necessarily better. Mechanical dial hourcounters don't do this. I actually don't understand the benefit of having one with an LCD readout?

I don't either - particularly since the hours only show when the engine is running.

Mark

Muckle Flugga · 07-06-2015, 07:17

Quote:

Originally Posted by colemj

I don't either - particularly since the hours only show when the engine is running.

Mark

Oh… Well, that's a bugger. And kinda pointless. Reminds me of a fellow comm skip who was stuck for a month at the Cat Club in Antigua when the brand new 70 footer he was tasked with had a glitch… it appeared that some bright spark had decided that the engine throttle/gear control needed to be wireless, despite being mounted in the conventional position directly over the engine room in easy morse cable distance. So… it just stopped talking to the clutch. Stopped them dead for a month until a new unit could be flown out and installed.

Useful as a chocolate fireguard.

Wrong · 07-06-2015, 07:27

On my Yanmar 2YM15 the ground to the hour meter and tach comes from the sail drive. I know because when I decided to bypass the wiring shroud rather than try to isolate wiring issues at the connectors, I assumed the sail drive wires were out of play and cut them... Wrong again...

Anyway, if your engine has wiring for the sail drive check the integrity of the wire and connections before dismantling your Tach.

sailsw00 · 07-06-2015, 09:01

Easiest and best thing to do is get mechanical ones to replace the LCD ones. They work.
-Steve

Fastmover2 · 07-06-2015, 10:32

This must be inherent in VDO Tachs with the LCD display. I have two Tachs and one displays hours and the other takes long naps. Of course now the hour meters are not in synch. Was going to have it repaired in Fort Lauderdale and the VDO repair facility quoted $190. When I asked what a new one costs, I could only imagine the look on his face when he told me $180. Guess walking upstairs to get the numbers on the other tach works for now.
What brand of mechanical counter did you get anyway?

Cadence · 07-06-2015, 10:47

Quote:

Originally Posted by peterp

I always log my engine hours on shutdown, recently the display was blank on one engine then a couple of hours later on arrival at our home marina the other display failed, the tacho's are working fine as is everything else, I checked the wires that go into the back of the tacho there is simply a removable plug with about four wires connected, I removed the plug checking for any loose wires or corrosion etc. all seems good, also noted that when I pushed the plug back in the light inside the tacho came back on so I know power is OK although I guess the hour meter could fail even though the light is on. Here is the odd bit the following week after a short run the hour meter came good all by itself with the correct hours displayed, I was pleased that whilst the display had failed the hours are being correctly accumulated. This weekend both hour meters have failed again. In summary I feel it is a connection problem but I think the connection is OK at the tacho end, I am unsure where the hours information comes from, my engines are 40 HP Yanmar 3JH5E about 230 hours total time Lagoon 400 about 4.5 years old, I did call Yanmar here in Australia they advised it would be rare for my problem. I would be most appreciative if anyone can help, or have experienced the same problem. Thanks in advance.
Regards Peter

Just for shits and giggles. Are the LCD displays in direct sun light? That can cause them to go blank. You may be chasing a ghost with nothing wrong.

Fastmover2 · 07-06-2015, 11:13

Good idea but no. Tach is in Pilothouse where the heat and AC are. Nicely shaded. Actually the one that works is on the bridge where the sun is.
I did note the new VDO Tachs have programmable engine hours so you can make them read whatever you want them to. Will fix it when the other one dies.

Stu Jackson · 07-06-2015, 11:21

Quote:

Originally Posted by Fastmover2

I did note the new VDO Tachs have programmable engine hours so you can make them read whatever you want them to.

Always a useful feature when selling!!!

Alsdo totally illegal in automobiles here in the US.

Cadence · 07-06-2015, 11:38

Quote:

Originally Posted by Fastmover2

Good idea but no. Tach is in Pilothouse where the heat and AC are. Nicely shaded. Actually the one that works is on the bridge where the sun is.
I did note the new VDO Tachs have programmable engine hours so you can make them read whatever you want them to. Will fix it when the other one dies.

Sorry, it was a thought. Hoped it was right. The ones that go click, click fail also.

colemj · 07-06-2015, 11:45

Quote:

Originally Posted by Fastmover2

I did note the new VDO Tachs have programmable engine hours so you can make them read whatever you want them to.

I just bought a new VDO tach and it doesn't have this ability. Maybe only certain models do?

They all have programmability for number of alternator poles, number of cylinders, etc - and have rpm adjustment, but I haven't heard of programmable hours before.

Mark