Engine hour clock - not working

icarusbop

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Hello:

After fixing my Perkins 4108 engine I have noticed the hour clock is not working.
Can anyone advise how they function? - I assumed when the engine is running and generating electric the power is applied to the clock and the clock advances - that simple.

As an extra - the rev counter is currently dodgy (it's on the list of things to fix) could this be associated with the hour clock fault?
Thanks

Ian
 
Even simpler I think. I fitted one and it is just wired to the ignition switch so just runs as soon as you turn on the ignition switch.
 
Some hour meters are wired so that they start running as soon as power is applied, but this means that they turn even if the motor isn't running.

The ones on my engine have a positive feed from the ignition, a negative to the battery and a run terminal that comes from the alternator warning light. Is your alternator warning light working correctly?
 
Some meters do take a pulsed input, but I think they are more common on aircraft engines.
Most of the marine gauges that I've looked at in the last couple of weeks are of the two or three terminal variety that I mentioned earlier.

If the problems are related, it could be a faulty ground return.

Pictures of the wiring might help (and the question regarding the alternator warning light still stands)
 
All:


Thanks for the advice - I'll have a look at the wiring and put a meter on it next time I am onboard which will be at the weekend.
Maybe the clock itself is broken.
 
What sort of "not working" not incrementing, or no display? If the latter, it is a well know problem, with a simple solution. Go to the Bavaria Yacht Forum site in my signature, click Downloads, then download the PDF "Replace Volvo Penta Hours LCD"


I see no reason why any of the digital ones cannot be used with a diesel as all they seem to need is a 12 volt feed whilst the engine is running...
That's quite hard for a diesel, it needs an enable signal from a device that uses the oil pressure sensor, or the tachometer feed. Much easier to use the ignition switch, if one is fitted.
 
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Are you sure its an electrical hour meter. The one on my Perkins 4108 works on the broken clockwork principal, when the engine vibrates the clock runs when it doesn't, it stops.

Plank
 
So I took a trip to the boat and did some testing.
The hour meter has only two connections +12v and 0v, there is power at the cables when the engine is running.
I took out the meter and connected it straight to a 12v feed - no movement.
so I know the clock is broken and can buy one from eBay, now the only annoyance is I really don't know how accurate the hour count for the engine is, the meter stopped at 2619.07, but we don't know how long ago the clock died, pretty much making my hour count useless right?
 
Pretty much. Not that it really matters on a 4108. Change the oil and filters every season and it'll keep on tickin' . Mine has got many thousands of hours on it, certainly more than 5000 but no idea how many actually.

My hour meter, recently reinstated, takes it's positive from the engine instument power and the negative from a contact on the oil pressure switch which is a changeover type.
 
I've ordered a new clock from Ebay.
When it arrives I'll stick it in and make a note of the hours from the old clock on it.
Thanks to everyone for help and suggestions.
 
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