wiring hourmeter on Diesel

[RW Sailor]

Hello,
I have a 12 hp Yanmar Diesel wired in my boat and recently got an hourmeter for it and only realized afterwards: Where do I wire it? I do understand that I need some point with Electricity - but only if the engine is running. So I thought ingnition, but as a Diesel doesn't need Electricity to actually run but only to start that doesn't work. Also the Alternator always has electricity.
So I thought maybe with a relay since there are higher voltages when the Alternator is running, but then also the solar pannels are going to run up to higher voltage...
any suggestions? Or is there a hourmeter out there that is running on vibration from the one cylinder engine? might be easier ;-)
Thanks a lot for the help already!
Manuel

[model 10]

Use an oil pressure switch to turn it on.

[RW Sailor]

that sounds like something that would work...
So I would have to buy an oil pressure - meter first and somehow wire it too that? I understand the idea, just not quite sure to push the idea into the reality

[Blue Stocking]

An ignition switch normally has 3 positions OFF-RUN-START. power it off the run position, which is probably where your alternator gets switched on from.

[model 10]

Originally Posted by RW Sailor

that sounds like something that would work...
So I would have to buy an oil pressure - meter first and somehow wire it too that? I understand the idea, just not quite sure to push the idea into the reality

NO , a simple oil perssure switch that is either open or closed. OIl pressure closes the contacts. 12v to the meter and the oil pressure switch makes the ground for the meter. A problem with using the start switch is , you can end up with the switch on for some reason and the meter will be running without the engine running. Auto parts store for this one.

[svinshallah]

Several years ago, I saw an hour meter where a small sensor was clamped around one of the injector lines. It ran off a small internal battery. I don't know if it is still available, but nothing could be simpler and it was cheap.

[svinshallah]

Sorry for the double post. Take a look at Design Technology, Inc., Home of the Tiny-Tach - Diesel Tiny-Tach Tachometer