Yanmar 1GM10 No Oil Pressure Light or Buzzer on Start/Stop

sailingjupiter

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When starting or stopping my Yanmar 1GM10 I don’t get either the warning light or buzzer coming as all other engines do. If I have been motoring a while when switching off it tends to come on. But under normal circumstances when only motoring short distances nothing.
Engine is well serviced and works faultlessly other than this. I noticed this after last years oil change and continues after this years too. Only difference to previous years is I put in some quality Shell HX5 Helix 15W 40. Could it be the engine just isn’t building the correct oil pressure on shorter running? I assume getting the light and buzzer a good thing and not getting it bad. Or does it not matter? As you can tell I’m no mechanic but do carry out the oil change myself using a genuine filter.
 
Probably nothing to do with the actual oil pressure in the engine as if that was deficient th engine would have died by now! Oil pressure comes up immediately the engine runs so short runs does not affect it.

Almost certainly electrical. The Yanmar panel and electrical connections are often poor so suggest you take all the connectors apart and clean them, particularly the one on the sender unit. It could also be the sender itself that has failed. If it helps I had the same problem, but intermittent on my 1GM, but still running after 30 years.
 
Easy to check the oil pressure wiring circuit. If you can find the oil pressure switch on the engine block, with the ignition on take the wire off the plug (should be yellow and white) and tap it on to the engine block. this should bring on the light and buzzer. If it does the wiring is all good, if it doesn't It would suggest the switch is faulty.
 
Easy to check the oil pressure wiring circuit. If you can find the oil pressure switch on the engine block, with the ignition on take the wire off the plug (should be yellow and white) and tap it on to the engine block. this should bring on the light and buzzer. If it does the wiring is all good, if it doesn't It would suggest the switch is faulty.

If it does the wiring and the panel are good, but the oil pressure switch is probably faulty.

If it doesn't then there is a problem with the panel or the wiring.
 
If it does the wiring and the panel are good, but the oil pressure switch is probably faulty.

If it doesn't then there is a problem with the panel or the wiring.

Of course you are right. I just didn't get down in words right what was in my head.
 
My brand new panel on my Shrimper 21 doesn’t sound when turned on prior to engine starting. Funnily enough they do sound when the engine is shut down. Still waiting to get a response from Cornish Crabbers.
 
My brand new panel on my Shrimper 21 doesn’t sound when turned on prior to engine starting. Funnily enough they do sound when the engine is shut down. Still waiting to get a response from Cornish Crabbers.

Possibly they are using circuitry I coincidentally designed for myself after installing a new engine. The oil alarm circuit is not directly energised when ignition is switched on. Only after alternator starts charging, a self-locking relay kicks in making the alarm active. It stays locked until the ignition is switched off - providing me with checking the oil alarm every time I stop the engine.
 
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Ah ha, I’ll chase CC up again and see what they say.

You might get more joy by contacting the Uk agents for Yanmar: EP Barrus

There may have been an "upgrade" to the panel along the lines that jiris suggests which is not reflected in any of the online owners manuals
 
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