Possible alternator/Charging problem on Barris Shire?

[David J Smith]

Good morning all. Recently we have noticed that the warning buzzer on the control panel is taking longer to go off. As it is continues 'chiruping' right up until 1100 RPM. By Chiruping, I don't mean the full buzz. With the inverter / charger switched on. It generally reads 12.6 when the engine is running at those revs. But when I rev the engine over 1100 RPM. The Chiruping stops. And the Charge says around 14 volts.  The engine is a 2007. But right now without the owners manual. I'm not sure what model it has. I can get any info you ask for. But all thats hid in the boat. And the wife is asleep.

So for now, I will wait for any responces from you please. 

Thanks David.

[Tony Brooks]

My first suspicion would be a failed diode. The nasty thing about failed dioses in alternators is that the alternator will continue to charge but at a slightly reduced voltage and maybe a third less current. What is the rated output of the alternator compared with the actual charging voltage at (say) 1500 rpm at first start of the day and the charging voltage some running hours later?

 

If you have an alternator specialist near you then taking it for testing may be the easiest way for most boaters.

 

There might be other causes relating to a possible parallel resistor across the warning lamp.

[David J Smith]

Thanks Tony. Another early bird. Is this diode easy to get at and replace please? David

[Tony Brooks]

15 minutes ago, David john Smith said:

Thanks Tony. Another early bird. Is this diode easy to get at and replace please? David

 

It is not just one diode, in most cases it is one from nine or one from six. They are probably grouped in sets of three permanently fixes to heat sinks. You would replace the whole heat sink assembly and that involves partially stripping the alternator and de-soldering connections and the re-soldering them. Whilst I am happy to do such things I can not recommend someone with little DIY experience tries it. 

 

It would also be worth checking the brushes. They are often part of the regulator but without a photo of the back of the alternator one can't be sure. On most modern alternators the regulator is held in place by one or two screws so is fairly easy to wriggle out. If brute force is used it is all too easy to snap a brush. If you find the/a brush is badly worn make sure that you physically check the state of the slip ring it runs on, they often groove and can wear through.

[rusty69]

Any chance it could be voltage drop caused by a poor connection? 

[nicknorman]

Presumably you have checked that the belt is not loose?

 

Otherwise I’m inclined to agree with Tony, the chirping suggests a diode issue.

19 minutes ago, rusty69 said:

Any chance it could be voltage drop caused by a poor connection? 

Unlikely because failure of the warning light to fully extinguish/alarm to silence suggests something internal to the alternator.

[David J Smith]

Thanks For all your advice guys. Which is totally over my old head. Looks like i need an expert to visit the boat. 

Cheers David 

[Tony Brooks]

1 minute ago, David john Smith said:

Thanks For all your advice guys. Which is totally over my old head. Looks like i need an expert to visit the boat. 

Cheers David 

 

Only if they can bench test the alternator and really know what they are doing. I have seen too many alternators with a blown diode passed as OK by mechanics on the basis that they appear to charge.  Taking it off is really just photo the back of the alternator, so you know where the wires go. Isolate the battery, disconnect the wires and insulate the large wire terminals, undo three bolts/nuts and lift off. Then take it to, or send it to a specialist. If they have an oscilloscope they could also look at the wave form and see that all three phases (generating coils) are working with it on the boat, but I have never seen a boat mechanic cum electrician take a scope to a boat.

.

[nicknorman]

9 minutes ago, David J Smith said:

Thanks For all your advice guys. Which is totally over my old head. Looks like i need an expert to visit the boat. 

Cheers David 

As you say, over your head but likely over the head of the average maintenance person you are likely to be able to get to your boat. Physically taking the alternator to a specialist company is the best way…

[rusty69]

Had ours looked at by driftgate in St Neots if you are anywhere near there, but it was a long time ago

Edited September 18, 2022 by rusty69

[Tony Brooks]

Just now, rusty69 said:

Had ours looked at by drifgate in St Neots if you are anywhere near there, but it was a long time ago

 

They should know what they are doing, after all they designed their own zero volt drop split charge "diode" system.

[David J Smith]

Thanks Nick. My engine has two alternators. One conciderably larger than the other.  So I don't know which one does what. 

[David J Smith]

Just now, Tony Brooks said:

 

They should know what they are doing, after all they designed their own zero volt drop split charge "diode" system.

Ah. Past through St Neots a long time back. On the Leicester arm of the GU moored at Weltonfield marina now. Know anyone in that area. Machanic here was a bit vague.. With "euwwwwwww, that sounds expencive". Just what I needed eh. Would it be something tha RCR could diagnose and possible fix?

[BEngo]

Post a photo on here so it can be identified.  Once you know what it is if you do not have a local auto electrical shop ring Lancashire Rotating Electrics.  They will arrange pick up, test it, repair if needed and return.  Usually very quickly and at a reasonable price.

 

N

 

 

[Tracy D'arth]

RCR from recent experiences couldn't diagnose if its raining or not.  If its the cabin alternator you are not covered by the way, they only will "get you going" not sort out problems.

Does your panel have 2 alternator warning lights? The smaller alternator is for the engine battery.

[Tony Brooks]

13 minutes ago, David J Smith said:

Thanks Nick. My engine has two alternators. One conciderably larger than the other.  So I don't know which one does what. 

 

OK, large one to charge the domestic bank & small one for the engine battery. Ideally you should have two warning lamps but some make do with one and that make sit difficult to see which alternator has the problem.

 

Try this. Each alternator will have one or two THIN wires connected to it. The big one probably one and the small one two (a few alternators are different). Remove and insulate both thin wires on one alternator (noting where they fit) and turn on the ignition and run the engien at 1500 rpm. If the problem goes away or if the offending one of a twin warning lamp setup fails to illuminate you have found the offending alternator - I think.

7 minutes ago, David J Smith said:

Ah. Past through St Neots a long time back. On the Leicester arm of the GU moored at Weltonfield marina now. Know anyone in that area. Machanic here was a bit vague.. With "euwwwwwww, that sounds expencive". Just what I needed eh. Would it be something tha RCR could diagnose and possible fix?

 

Why am I not surprised at that - a past Weltonfield moorer.

Edited September 18, 2022 by Tony Brooks

[nicknorman]

25 minutes ago, David J Smith said:

Thanks Nick. My engine has two alternators. One conciderably larger than the other.  So I don't know which one does what. 

The large one will be charging the domestic batteries that feed the inverter charger. So if the cessation of chirping coincides with the jump of voltage up to 14v then it’s highly likely to be the large alternator.

Normally there is a red warning light for each alternator. When the chirping is happening it’s likely that one of the lights will be glowing faintly - you might have to shield it from daylight to see it. The manual should tell you which light is for domestic (large alternator) and which for engine (small alternator).

Edited September 18, 2022 by nicknorman

[Tracy D'arth]

Difficult to give advice when we don't know where you are Mr Smith. Second for Lancs RE, excellent service.

[David J Smith]

9 hours ago, nicknorman said:

Presumably you have checked that the belt is not loose?

 

Otherwise I’m inclined to agree with Tony, the chirping suggests a diode issue.

Unlikely because failure of the warning light to fully extinguish/alarm to silence suggests something internal to the alternator.

Just had the Engine serviced. I will check though.Thanks

8 hours ago, Tracy D'arth said:

RCR from recent experiences couldn't diagnose if its raining or not.  If its the cabin alternator you are not covered by the way, they only will "get you going" not sort out problems.

Does your panel have 2 alternator warning lights? The smaller alternator is for the engine battery.

No. Only one volts gauge

[nicknorman]

2 hours ago, David J Smith said:

Just had the Engine serviced. I will check though.Thanks

No. Only one volts gauge

A picture of your panel would be good. Even though there is only one “volts gauge” there are likely to be 2 warning lights.

There is variation in the panel design according to age, but it might look like this. You can see the 2 alternator charge warning lights near the bottom

 

Edited September 18, 2022 by nicknorman

[Wanderer Vagabond]

9 hours ago, David J Smith said:

Ah. Past through St Neots a long time back. On the Leicester arm of the GU moored at Weltonfield marina now. Know anyone in that area. Machanic here was a bit vague.. With "euwwwwwww, that sounds expencive". Just what I needed eh. Would it be something tha RCR could diagnose and possible fix?

From my own experience and where you say you are,I'd strongly recommend Electrostart at Daventry (https://electrostart.co.uk/). They seem to know what they are doing with alternators and if you need a replacement, their prices are competitive. (No I'm not on a commission, but they've solved my alternator issues in the past). 

[roland elsdon]

Beat me to recommendation!!

They do outright sales that means you can keep the functioning but failing as a get you home special. Which i have found handy, and did a bloke i met needing an alternator one day!

[David J Smith]

10 hours ago, Tracy D'arth said:

Difficult to give advice when we don't know where you are Mr Smith. Second for Lancs RE, excellent service.

I did say My boat was moored in Weltonfield on the leicester arm of the GU

11 hours ago, Tony Brooks said:

 

Only if they can bench test the alternator and really know what they are doing. I have seen too many alternators with a blown diode passed as OK by mechanics on the basis that they appear to charge.  Taking it off is really just photo the back of the alternator, so you know where the wires go. Isolate the battery, disconnect the wires and insulate the large wire terminals, undo three bolts/nuts and lift off. Then take it to, or send it to a specialist. If they have an oscilloscope they could also look at the wave form and see that all three phases (generating coils) are working with it on the boat, but I have never seen a boat mechanic cum electrician take a scope to a boat.

.

Thanks again Tony. Looks like the way to go.Cheers Dave

[David J Smith]

2 hours ago, nicknorman said:

A picture of your panel would be good. Even though there is only one “volts gauge” there are likely to be 2 warning lights.

There is variation in the panel design according to age, but it might look like this. You can see the 2 alternator charge warning lights near the bottom

 

Great picture of a more up to date panel than I've got. Mine don't have those 4 red warning lights. Can't send a picture,as i'm at home right now.

Thanks Dave

11 hours ago, BEngo said:

Post a photo on here so it can be identified.  Once you know what it is if you do not have a local auto electrical shop ring Lancashire Rotating Electrics.  They will arrange pick up, test it, repair if needed and return.  Usually very quickly and at a reasonable price.

 

N

 

 

I can't right now. As i'm not on board the boat.I'm back home in suffolk. Thanks anyway. Dave

[Tony Brooks]

To make it far easier to identify any future faulty alternators I would suggest that once this problem is sorted you look into getting a second warning lamp fitted. It will involve a simple relay and a small wiring modification.