Yanmar Engine Alarm

[eebygum]

Any advice on why my Yanmar Engine alarm is going off on engine shutdown ? case notes below:

Boat launched 3 weeks; since then two or three 20 min run outs in the marina. No problem. Battery on, key turned, low oil light and alarm comes on, start engine and alarms goes off. Run engine ok, stop engine, low oil alarm comes on, turn key to off and alarm stops.

Took the boat out Saturday, two hours on the engine; quite a bit at high revs to beat tide and also testing log caliberation in marina against GPS SOG. Shut down OK as above.

Tried starting Sunday, had trouble starting. Starter Motor just seemed to click. Eventually started on both batteries. After running for 20 minutes, switched off and Yanmar Oil, Water and Charge light on, Alarm on; turning key off made no difference. Alarm only stops when battery switched off.

Repeated above step, noticed the charge light is not on while engine running and no apparant charging of the batteries even under load. Batteries also quite low given the engine running the previous day. Slight electrical smell and suspect therefore that alternator is goosed after the long Saturday runout (believe engine had not been used by previous owner very heavily).

Swapped alternator out with backup tonight - Charging light on, and batteries showing charging; Great. But .................when I stop the engine that bloody alarm goes off again and the Oils, Water and Charge lights come on again. Checked oil - OK, water pumping out is fine - clear and no oil, no smoke; could it still be the Charge - if so what, or is there some reset I need to do /forums/images/graemlins/confused.gif

Thanks in advance
Andrew

 

[TheBoatman]

Andrew
Don't worry about the alarms -they seem to be working perfectly.

When you switch the ignition on "all alarms" go off (buzzer) because you don't have any charge (alternator not turning), oil pressure (because engine isn't running) BUT when you start the engine after a couple of seconds the alternators running - so it's alarm goes silent, the oil pump is running - so it's alarm goes silent.

But when you stop the engine you are no longer producing any charge or oil pressure so the alarm(s) will sound. On Yanmar engines this can vary from 2-5 secs after the engine has stopped.

Think of it this way when you stop your Yanmar you pull a stop but "don't actually" turn the ignition off- go to your car and turn the ignition on and look at what warning lights are on - then start the engine - all the lights go off. Then switch the engine off to stop the engine but then immediately turn it on again -what you will get is all the warning lights back -the only difference is Yanmar have a warning buzzer, which is the bit that's bugging you.

Don't worry all is fine and dandy.

Peter.

 

[Koeketiene]

Don't worry about it - seems to be "normal" for Yanmar.

Ours does the same.

 

[ex-Gladys]

I don't believe what is happening IS all fine and dandy.... If you have stopped the engine and switched the key to off AND the alarms still continue to sound until you isolate the battery then there is a wiring problem or switch problem

 

[salamicollie]

Agree - sounds like a switch problem - You don't say which engine or which panel you have. But if it is one of the small engines and simple panel with no Tacho the switch on the panel could be u/s which would also explain the difficulty in starting. If the panel with the tacho ther is also afaik a lamps test switch that could also cause this.

Of course the problem could be elsewhere in the wiring!

 

[fireball]

I'd be concerned at the electrical smell down below as well - it certainly sounds like you need to checkover your complete engine electrical system. I would run the engine for a bit then use my nose to locate the source of the smell, if it is the alternator as you think it may be then whip that off and get it tested - shouldn't cost more than few quid to run it up ...
If you had to start on both batteries then it could be 1) your alternator isn't charging it up and the battery has run down (unlikely given the data above). 2) the battery is dead and needs recon/replace or 3) you have a short somewhere (could be in the alternator and explain the electrical smell and buzzer??) which has drained it.

 

[Topcat47]

If the alarm is still sounding after the switch is off and you have a flat battery, it sounds like a short in the switch itself to me. Check it with an ammeter in the circuit. Engine switched off there should be no power to the alarms.

BTW the engine also has a high temperature alarm (thank god) for when you have cooling water problems.

 

[NickHarley]

Don't know about the charging problem, but if the alarms continue after you've turned everything off (with key) then, as mentioned, you've got a switch problem.

I've got a mid 80s yanmar 1GM10 with the simple (no tacho) switch panel, & have had problems with it. If you have similar set-up its worth taking a look... the key goes into a small switch-cylinder than can be easily taken out & (not so easily) unclipped/taken apart. The key turns a disc of copper that then contacts with a fixed piece of copper, forming the circuit. Two possibilities... the rod/connection turning the disc has broken, or there is something shorting the switch (seawater?!), so turning it off may not break connection. Worth a look/clean anyway?

I guess a short might even explain some other symptons - flat batteries etc.?

Good luck anyway.

 

[eebygum]

Thanks for all the advice; yes it definately sounds a bit suspect that the alarm continues AFTER the engine is switched off at the key.

At least the alternator seems to be charging now and I can get the original checked out while the backup is on (best fourty pounds I've spent off ebay !)

Unforynualey electrics never was my string point /forums/images/graemlins/crazy.gif

Cheers