Mysterious unlabelled dashboard warning light turns on, don't know the cause

[Noam Chomsky]

Hi everyone,

 

I hope some engine-clever people can help me figure this one out. A few weeks ago I was cruising on my boat, when for the first time ever a red warning light on my dashboard came on. Unhelpfully, this light has no label - and as it's remained off for the two and a half years I've owned this boat, I have no idea what it means. I knew it couldn't be good, but there was no chance of mooring for another hour, so I plunged on, then had to leave straight away. I did check the battery voltage on my electronic display, and everything seemed fine in that department, so I assumed it must be an oil problem.

 

Yesterday I checked my oil - it was black, so I changed it, and for good measure I filled it all the way to the maximum level. I then started the engine with some high rev in neutral, and the warning light came back on! I idled the engine, and the light disappeared. I slowly added to the rev until the light started blinking, then added more 'til the light came on solid.

 

At this point I wondered if it was just a case of leaving the new oil to circulate for a while, so I left the engine on idle for half an hour - to my dismay, when I came to look at the dashboard again, that light was a solid red, even on idle!

 

All the while, the batteries seem to be charging fine. So unless the fuel filter needs changing, I've run out of ideas. The engine in question is an air-cooled Hatz (link: http://www.hatz-diesel.com/en/products/diesel-engines/l-series/product/details/name/2l41c/) and it's always been incredibly quiet. It's between 5 and 7 years old, and it's a beaut. The last thing I want to do is kill it through ignorance - can anyone suggest what this warning light might be saying? If it's practical, I'll buy a beer for whoever helps me get to the bottom of this. If it isn't practical, I buy you one as soon as it is.

 

Thanks a lot,

Noam

[Starcoaster]

Do you have a picture of the dashboard itself? It could be the light to say the alternator isn't working, or that the power to the horn is on or anything, depending on the panel- those are the two mystery lights on mine, but I suspect every dashboard is different.

Edited October 30, 2013 by Starcoaster

[MtB]

Try following the wire(s) from the red lamp back to wherever it is getting it's electricity from. This should provide a Big Clue. Is it a switch? A sensor? Or something else?

 

MtB

[BlueStringPudding]

Temperature gauge? Coolant problem maybe.

 

Or diesel level, at a push? Maybe your movement was rocking the boat causing the diesel level, if low, to slop into critical?

 

Failing that maybe the alternator is pooped.

Edited October 30, 2013 by BlueStringPudding

[MtB]

Actually it is quite likely to be a liquid level sensor, I'd say either oil or coolant..

 

When your rev the engine the circulating pump runs faster, sucking the liquid away quicker causing the reservoir level to fall slightly, and the 'low level' warning lamp comes ON.

 

MtB

[Sir Nibble]

Sounds like a coolant level light to me but symptom suggest it COULD be oil pressure. First things first, has it come on in the past with ignition on and engine stationary? If not then it's not oil and I would look at the coolant level. failing that it needs tracing to source.

[Noam Chomsky]

Thanks for the quick responses, guys.

 

@Starcoaster: Here's a picture of the dash, although I think this will only add to the mystery (my apologies for the shoddy camera work):

 

@BlueStringPudding: Don't think it's diesel, as I've run out of diesel twice, and it would have been very useful both of those times if a light had come on to warn me. Temperature seems unlikely to me given that it happened literally the moment I turned the engine on, but maybe it's indicating a problem with the airflow, this being an air-cooled engine?

 

@Mike, you're right, that's a sure-fire way of finding a Big Clue. I can't open the dashboard right now, but I can this weekend. If this is because of a liquid level sensor, and my oil is at max, could this just be a case of leaving the engine on until the light goes away? That would be heaven. As the Hatz is air-cooled I don't think there's any liquid coolant in there - the manual didn't mention any. The other thing I could do is check the oil level again - there could be a leak?

 

@Sir Nibble - just put the key in, but didn't turn on the engine. The light didn't come on. It has a very eccentric way of starting up though, I'm not entirely sure the key does that much - this engine doesn't need any kind of warming, you literally turn the key, pull a knob and it jumps into life.

 

Thanks again for the help everyone.

Edited October 30, 2013 by Noam Chomsky

[Caprifool]

Poo level?

[Noam Chomsky]

Trying to figure out if there's coolant in the engine, I see an "oil cooler" on this diagram that seems a long way from the air filter:

Any clues here?

I think the air filter might need to be cleaned. I'll follow the warning light's wire to see if it looks like a likely suspect. Thanks everyone.

[MtB]

Bilge water level?

 

Simplest solution is buy another boat, I reckon

 

 

MtB

[Starcoaster]

Is that button bottom right of the pic that looks like a light the one that comes on? Do you know what make the dashboard is?

[Trento]

When you changed the oil, did you change the oil filter . If not thats the problem its an oil pressure warning light. (I think)

[Noam Chomsky]

Thanks Trento. I didn't change the filter. If I need to make one more journey before I change the oil filter, am I risking my engine's life?

[SamKingfisher]

Oil pressure is different to oil level. I'm no expert but it sounds like a possible oil pressure problem.

 

Look for a leak, but could be lots of internal stuff that isn't leak related.

Thanks Trento. I didn't change the filter. If I need to make one more journey before I change the oil filter, am I risking my engine's life?

Not likely

[rjasmith]

I know it doesn't seem helpful always to suggest looking at the manual! Perhaps you don't have a paper copy?

 

I took a look at that link you gave in post #1 because I don't know this engine and was curious. From the page that comes up there is a link to the full operators manual so I had a quick scan through it.

 

It seems these engines have a simple ECU which monitors all sorts of things! The manual is very impressive and has a good faults diagnosis (section 9 page 93). The ECU seems to have a panel with quite a few indicator lights on it. Does your engine have this on it? Maybe these lights have outputs that can be fed to the boat dashboard as an engine fault common alarm (ie your unlabelled red light).

 

I would certainly have a read of the manual and see where that leads you!

 

Richard

[Justme]

I didn't change the filter.

 

If I need to make one more journey before I change the oil filter, am I risking my engine's life?

 

 

Not likely

 

 

I would say likely.

 

Old oil was black & thick so filter could be clogged up.

 

If the bypass fails or it does not have one then oil flow to the engine will be compromised.

[ditchcrawler]

Would you drive your car home with the oil light on?

[Radiomariner]

Bilge water level?

 

Simplest solution is buy another boat, I reckon

 

 

MtB

Carefully remove the red light, and put it somewhare safe. It works. Get rid of the boat, it might not be working properly!

 

I think you can safetly ignore coolant problems, however I seem to recall a little air cooled Hatz at a shoreside radio station I once worked at. (It was the small engine used to pump up a small air bottle which would air start a larger generator set) It used to have a red light on the panel when it overheated in hot weather (In the tropics). We used to leave running for five minutes after the light came on, because, if we stopped when it first came on there would not be enough air in the bottle for two attempts at starting the main generator, (a requirement). To stop and wait for it to cool down was not an option. To be honest, I did not know, (or at that time care) where the sensor for the light was or whether it was a standard fitting. There was another light I think was for oil pressure that I never saw lit up It was back in the 1960's) Sorry cant be more help

 

Just had a little flag up to say that three more replies have come in since I started typing this, Clever. never seen that before

Edited October 31, 2013 by Radiomariner

[Dave Payne]

Would you drive your car home with the oil light on?

 

Yes, once, didnt end well....

[Radiomariner]

Would you drive your car home with the oil light on?

SWMBO has, frequently!

[Phil Ambrose]

 

Yes, once, didnt end well....

So did my wife, twice!! did'nt end well on either occasion.

 

Phil

Edited October 31, 2013 by Phil Ambrose

[Bee]

Change the filter asap, this is a must. if no better suspect the sender, little brass thingy with a wire or two going to it, check the wire colour, see if it emerges behind the warning light.

[J R ALSOP]

I think it is a dodgy flasher bulb, does it go off when you have completed a turn?

[nb Innisfree]

I used to own a car than was heavy on oil and when it was low I had to corner gently to stop the oil light coming on.

[Denizen of the Deep]

Only yesterday I took advantage of the fact that I had an electrical engineer on board, after the scheduled job was finished, to ask him to identify the unlabelled red light on my panel. He followed its cable right down to the side of the engine behind the air filter, where it connected to a fairly large sensor. He thought it might sense air pressure at the engine inlet and close when pressure was too low. We started the engine and he blocked the air intake with his hand. Bingo! The mysterious light went on. Engineer remarked that he had never before come across a 'blocked air intake' warning on a boat.

 

Maybe that's what you have?