Tamd61A - Hours meter, what does it work off?

[Murv]

One of mine has recently stopped working. Is it just a timer within the tacho or does it pick up something from the engine?

 

[Momac]

VP hour meters on the non electronic engines are a timer .
It is quite usual for the display to fail. It may come back to life with a bit of sunshine.

 

[Murv]

Great, thanks Martyn.
Is it worth me having a quick (small) spray behind the unit with WD40? It's a very recent failure, the surveyors reported only showed a 4 Hour difference between the 2 engines, but it's not moved since!
I just have to be mindful of resale value if it's not showing engine hours.

 

[KevB]

The 'normal' issue with the VP hour meter is the display fades to nothing but it does continue to register the hours. There is a thread somewhere on here showing how to replace the LCD.

 

[Momac]

It really is such a common fault . It would almost be surprising to find a twin engine boat with both/all the VP hour counters working .
As said it will still be counting the hours even if the display is asleep.

I wouldn’t use WD40 but perhaps could try a contact cleaner spray with leaves no reside . Like this..................
http://cpc.farnell.com/1/1/31336-100005000-200ml-aero-klene-50-200ml-servisol.html

.
Or could try take the tachometer home and put it in a warm dry place for a week.
Or do nothing and it may come back to life all by itself.
You would think VP would make the tachometers water proof but the need seems to have escaped them.

 

[Murv]

Thanks both, this is a mechanical unit though, it's a 1989 boat.
I did wonder how drying it out would help!
Thanks for the link, I do have some electrical switch cleaner, I'll try a blast with that first and see if's just got sticky.

The boat sat for a long time before I bought it, I imagine it's possible that the hours meter has just got stuck due to lack of use? One of the rev counters took a few minutes to wake up on the sea trial as well (it's fine now)

 

[KevinT1]

http://www.ybw.com/forums/showthread.php?450990-Volvo-Penta-Engine-Hours-LCD

and

http://www.ybw.com/forums/showthread.php?448124-Engine-hours/page4

The connection to the LCD is affected by moisture, when it starts to fail then you may get odd times when it is dry that it will work ( airing cupboard / summer sun ) but long term you will need to replace the LCD

The hours are stored on the Tacho, so even if the LCD is blank you are still counting the hours. Replacing the LCD maintains your overall engine hours

Kevin

 

[oldgit]

Not sure Murv think your meters are analogue and on my 40A there was sensor on the engine.....bit like a temp sender unit.
I frequently managed to knock it off when messing about in engine compartment therefore losing rev counter on that engine. ?

 

[Murv]

Not sure Murv think your meters are analogue and on my 40A there was sensor on the engine.....bit like a temp sender unit.
I frequently managed to knock it off when messing about in engine compartment therefore losing rev counter on that engine. ?

Thanks Fred, they are analogue meters.
The rev counter is working fine though, could it be the counter itself is just sticking? i.e when the tacho unit is powered up, an internal clock in that unit drives the counter around and it's got stuck? Or, is it reading from the engine to get the hours count?
I have been scrabbling around between the engines recently...

 

[Trundlebug]

I have mechanical counting hour meters on my 1988 boat.

They seem to work just from an electrical feed, i.e. if the ignition is switched on, they count.
The engine doesn't have to be running.

So check the supply to the counter, if OK give it a tap to free it off

 

[Murv]

Excellent, thank you

 

[Racingfrank7]

As far as I know regardless of which rev counter you have it runs off the alternator w wire normally grey.
The frequency changes with the rpm.
Some engines do have a hall sensor and a disc I do believe tho.

 

[rosssavage]

on my 1988 TAMD61A's the feed is just off the ignition. Ignition on = hours counting, whether the engine is running or not.

The tacho feed is a Hall effect sensor down by the injection pump drive - not relevant to hours meter though.

 

[Murv]

on my 1988 TAMD61A's the feed is just off the ignition. Ignition on = hours counting, whether the engine is running or not.

The tacho feed is a Hall effect sensor down by the injection pump drive - not relevant to hours meter though.

Thanks Rossavage, I'll check the feed tomorrow and give it a squirt with the switch cleaner.
I must admit I forgot all about it today, too busy enjoying the sunshine!

 

[oldgit]

Switch cleaner Good.
WD40 Bad.