Rev counter stopped working.

[Slow and Steady]

Me again!

It worked... now it doesn't. It's a VDO.

I'm new to diesel engine rev counters attached to the alternator.

It's a std beta 43 engine and alternator from 15 years ago. The engine only has a few hundred hours on it.

So far I've:

Read up a bit about this kind of rev counter,

Pulled the plug off the alternator and checked continuity of the wire to the rev counter, checked for corrosion in that plug (sealed with white grease, all good),

confirmed the alternator is charging the battery.

Checked the rev counter was getting volts... but didn't realise I should have set my meter to AC so the jury is out on that one.

Checked the +ve and -ve connections to the rev counter are doing what they should. I suspect the +ve is just for it's light?

Given up while I ponder.

 

Does anyone know if there's a way to check the actual rev counter itself other than confirming it gets the signal and doesn't work? I don't want to replace it only to find it still doesn't work and also would like to keep the recorded engine hours. It's quite old but hasn't had a lot of use, this boat has been a home more than a boat over it's life.

 

Thanks for reading.

 

Pic of the alternator/socket if that helps... No, I'm not responsible for the crimp connector on the brown wire or the electrical tape on the red one.

The signal for the rev counter is the blue/black one.

 

Edited January 7, 2022 by Slow and Steady

[TheBiscuits]

Loom multiplug connection.  

 

Follow the wires from the control panel to a large bulge caused by two rubber boots.  Separate the boots and you'll find a multiplug inside it.  Separate the plug & socket, clean all the connections and put it back together firmly.

 

Test everything, and if it's working tie-wrap the two parts of the plug firmly together and carefully slide the boots back over the join to waterproof it.

[Slow and Steady]

1 minute ago, TheBiscuits said:

Loom multiplug connection.  

 

Follow the wires from the control panel to a large bulge caused by two rubber boots.  Separate the boots and you'll find a multiplug inside it.  Separate the plug & socket, clean all the connections and put it back together firmly.

 

Test everything, and if it's working tie-wrap the two parts of the plug firmly together and carefully slide the boots back over the join to waterproof it.

Ah-Ha - yes - thank you - I remember now you mention it that I've done that, the multiplug is close to the rev counter and I had to peel back those boots to trace the wiring as it's all just 2 colours back there. I think it may have been silly to start this thread before going back and confirming the signal at the tach end with the AC setting. When the weather cheers up...

 

Meanwhile I still would like to know if there is a test I can do on the rev counter itself. Maybe some kind of continuity between signal and -ve... or something... I'm guessing but I can't think how I could test other than borrow someone's rev counter and wire it up in place of mine. It's really the engine hours that I'd like to keep, the rev counter isn't particularly expensive and I do have the relief that the alternator is working which was my initial concern.

[matty40s]

You may well find it is connected to the other condensation issues you have.

Beta rev counters are notorious for the hour meter not showing display in winter, and the rev counters can stop working until a dry warm day.

[TheBiscuits]

1 minute ago, Slow and Steady said:

Meanwhile I still would like to know if there is a test I can do on the rev counter itself. Maybe some kind of continuity between signal and -ve... or something... I'm guessing but I can't think how I could test other than borrow someone's rev counter and wire it up in place of mine.

 

Run a known good piece of wire between the tacho and alternator signal connections.

[Tracy D'arth]

Most Beta looms have 2 multiplugs, one near the panel the other near the engine.

If this is a digital display tach, they are notorious for packing up in winter. You could try taking it out and keeping it warm and dry for several days.

To test the tach.   If there is a + and - battery supply to the electronics you should get some sort of display, try shining a torch on it.

If you have a signal generator you could try feeding an AC signal at around 4kHz and 8v level in the signal connection.

[Slow and Steady]

21 minutes ago, matty40s said:

You may well find it is connected to the other condensation issues you have.

Beta rev counters are notorious for the hour meter not showing display in winter, and the rev counters can stop working until a dry warm day.

Thanks for the reply.

All my tests and the tach not working were at the height of summer and the engine room is about the driest part of the boat, I've never seen condensation in there.

19 minutes ago, TheBiscuits said:

 

Run a known good piece of wire between the tacho and alternator signal connections.

I've jumped the gun the gun by posting before testing the signal at the tach end with my meter set to AC haven't I? At the alt end I'd have to cut a wire to do as you suggest. Not keen of that, I better do the AC test, it's supposed to be 7.5-9v according to the Beta manual. I'll try and do this later today.

11 minutes ago, Tracy D'arth said:

Most Beta looms have 2 multiplugs, one near the panel the other near the engine.

If this is a digital display tach, they are notorious for packing up in winter. You could try taking it out and keeping it warm and dry for several days.

To test the tach.   If there is a + and - battery supply to the electronics you should get some sort of display, try shining a torch on it.

If you have a signal generator you could try feeding an AC signal at around 4kHz and 8v level in the signal connection.

See above reply to Matty about the weather/time of year.

I guessed there would be another multiplug as the wire changes colour, but I can't see/find it. Access is poor with a lot of permanently fixrd panels. I can only get at the engine from directly above.

No signal generator on board!

Are you suggesting that perhaps the engine hours counter should show a reading with the ignition on whether the engine is running or not? That would be a very easy test, thank you! If the engine needs to be running it's just as easy, I'm just interested in the running/not running - knowledge is power.

Edited January 7, 2022 by Slow and Steady

[TheBiscuits]

1 minute ago, Slow and Steady said:

Are you suggesting that perhaps the engine hours counter should show a reading with the ignition on whether the engine is running or not?

 

Yes, the engine hour counter is really just an ignition on counter.  If it has power on the signal pin it counts, which is close enough for general use - especially if your control panel squawks or beeps when the engine isn't running but the ignition is on.

[Tracy D'arth]

3 minutes ago, Slow and Steady said:

 

Are you suggesting that perhaps the engine hours counter should show a reading with the ignition on whether the engine is running or not? That would be a very easy test, thank you! If the engine needs to be running it's just as easy, I'm just interested in the running/not running - knowledge is power.

Yes but may be dim, hence the torch trick.

[Slow and Steady]

5 minutes ago, Slow and Steady said:

 

Oops, false post.

Edited January 7, 2022 by Slow and Steady

[TheBiscuits]

 

Note that 0.1 hours on the counter is 6 minutes, so you'll have to leave the ignition on for a while to notice a change unless you are very lucky in your timing.

[Tracy D'arth]

3 minutes ago, TheBiscuits said:

 

Note that 0.1 hours on the counter is 6 minutes, so you'll have to leave the ignition on for a while to notice a change unless you are very lucky in your timing.

Ah, yes, decimal time. I blame Plato.

[doratheexplorer]

With a name like @Slow and Steady what do you need a rev counter for?

[Eeyore]

Does this help? Even the latest type can still be folded back over the bell housing to the "common" location.

Edited January 7, 2022 by Eeyore

[Slow and Steady]

1 hour ago, TheBiscuits said:

 

Note that 0.1 hours on the counter is 6 minutes, so you'll have to leave the ignition on for a while to notice a change unless you are very lucky in your timing.

Oh!  Thanks for that, I didn't realise I had to see it change, thought it was a see numbers or not thing. It'll have to wait until tomorrow now, it's getting dark and it keeps hailing!

58 minutes ago, doratheexplorer said:

With a name like @Slow and Steady what do you need a rev counter for?

It annoys me that it doesn't work? + the hours counter, but you are right - with only one skin tank connected we never get much above tickover. It's handy for the travelpower too if we're parked up using power tools and lastly - I like gauges. 

26 minutes ago, Eeyore said:

Does this help? Even the latest type can still be folded back over the bell housing to the "common" location.

It might, thanks - we have 3 alts though (starter, domestic, travelpower) and I the starter battery one is right over the other side. I know there is some redundant wiring into a loom around the starter alternator location  so who knows. 

 

Edited January 7, 2022 by Slow and Steady

[gabble]

Is anything else charging the battery? E.g. shore powered battery charger or solar? My rev counter goes weird when something else is putting more charge in or the alternator has turned itself off. In my case it shows approx twice the actual rpm which is a bit disconcerting to begin with.

[Slow and Steady]

3 hours ago, gabble said:

Is anything else charging the battery? E.g. shore powered battery charger or solar? My rev counter goes weird when something else is putting more charge in or the alternator has turned itself off. In my case it shows approx twice the actual rpm which is a bit disconcerting to begin with.

Hi, thanks for the suggestion but no, I've been up and down the canal and it doesn't work. It packed up about 6 months ago - it was working at the end of one trip, next time I started the engine it wasn't.

[TheBiscuits]

4 hours ago, gabble said:

Is anything else charging the battery? E.g. shore powered battery charger or solar? My rev counter goes weird when something else is putting more charge in or the alternator has turned itself off. In my case it shows approx twice the actual rpm which is a bit disconcerting to begin with.

 

Many tachometers used on boats show a meaningless needle position when power to the control panel is switched off.  It's just the final surge in the signal circuit that makes the needle freeze somewhere on the dial.

 

As long as it resets to zero when you turn the ignition on (before starting the engine) it's normal.  You only have a problem if it keeps moving when your charger is running at different voltages. 

[bizzard]

Peerhaps he's retired, the Reverend Counter that is.

[Eeyore]

There is another possibility. The first photo shows that the brown ignition feed to the alternator has been rewired using a red cable, most likely due to a fault in the original brown cable. The three cables from the alternator plug are wrapped together in the loom, so the damage to the brown cable may have affected the black/blue strip cable at that time; but not enough to cause its failure straightaway. A photo showing some of the "redundant" cables might be helpful.

Edited January 8, 2022 by Eeyore

[Iain_S]

If the leisure alternator has a "W" connection, a temporary length of wire from the rev. counter to said connection should prove whether or not the instrument is working. It won't be accurate, though!

[Slow and Steady]

30 minutes ago, Iain_S said:

If the leisure alternator has a "W" connection, a temporary length of wire from the rev. counter to said connection should prove whether or not the instrument is working. It won't be accurate, though!

Good idea, why didn't I think of that!

[George and Dragon]

On 07/01/2022 at 13:45, matty40s said:

Beta rev counters are notorious for the hour meter not showing display in winter

Intermittently have the same issue on a Barrus Shire. 

[Leemc]

On ours, whether or not the key is left in when the engine is running makes a difference. If you take the key out when engine running, the needle doesn't move and LCD display doesn't work!

[Tony Brooks]

48 minutes ago, Leemc said:

On ours, whether or not the key is left in when the engine is running makes a difference. If you take the key out when engine running, the needle doesn't move and LCD display doesn't work!

 

That is to be expected because the instrument needs a +, - and pulse feeds. Remove the + and it stops working, often sticking at the point the + feed was removed.

 

I am not clear if the OP has had  a good look at the + and - feeds to his rev counter. A loose connection on any oen of the three cables  could easily cause intermittent operation.