Alternator issue

[Ynot]

I have a Beta 38 engine in a narrowboat 3 years old.

 

The boat has only been used for periodic cruising - around 500 hrs running.

 

It has not been out since November last, though the engine has been run a couple of times. I have had a 3 stage charger keeping the domestic batteries topped up but I ran it yesterday and noticed the warning light for the 100 amp (domestic)alternator was glimmering on and off.

 

Checked the connections on the alternator and the plug & sockets and all seem well. Tensioned the drive belt, though it looked ok, but I still have the problem. Have now removed the alternator and taken it home but not sure what to investigate on it as the likely cause.

 

Any thoughts?

[Gibbo]

Take the brush pack out and clean up the slip rings. You might be lucky.

[Chalky]

Did you see what the volts and amps were doing? It could be the belt was slipping. Even though they look ok they can slip silently. Is it a v-belt or a more modern ribbed belt. The older traditional belts would struggle with a 100A alternator, although if you've got a charger it may not be the belt.

[Ynot]

Take the brush pack out and clean up the slip rings. You might be lucky.

 

Thanks for that Mr G, I'll see if I can take it apart this evening. I take it if thats not the problem it could be expensive?

 

Chalky thanks, its a ribbed belt and I have tensioned it to no avail.

 

John

[Gibbo]

I'll see if I can take it apart this evening. I take it if thats not the problem it could be expensive?

 

Probably not actually. Even a new regulator and diode pack is very unlikely to break the bank. A service exchange isn't even that expensive. Certainly don't lose any sleep over it.

 

PS. It would have been easier for us to diagnose if you'd left it on the engine whilst we got you to run a few tests

[Ynot]

Probably not actually. Even a new regulator and diode pack is very unlikely to break the bank. A service exchange isn't even that expensive. Certainly don't lose any sleep over it.

 

PS. It would have been easier for us to diagnose if you'd left it on the engine whilst we got you to run a few tests

Aha! Well I'll try cleaning it up and reinstall. Hopefully I wont need further help. Thanks

[Nightwatch]

I had a problem with one of our units (can't spell alternator). I took it out and went to a local alternator fixer and he refurbed it. I think it cost £37/38. I was impressed.

 

Works okay. i must admit i was fearing a replacement at about £120/150. Give it a try.

 

Martyn

[Sir Nibble]

I had a problem with one of our units (can't spell alternator). I took it out and went to a local alternator fixer and he refurbed it. I think it cost £37/38. I was impressed.

 

Works okay. i must admit i was fearing a replacement at about £120/150. Give it a try.

 

Martyn

That used to be a significant part of my job, always worth a try, a good repairer will be quite straight with you about how economical a repair is versus replacement.

[ditchcrawler]

I had a problem with one of our units (can't spell alternator). I took it out and went to a local alternator fixer and he refurbed it. I think it cost £37/38. I was impressed.

 

Works okay. i must admit i was fearing a replacement at about £120/150. Give it a try.

 

Martyn

Good place in Daventry

Electroparts

6 Alvis Way

Daventry

Northamptonshire NN11 8P

[Ynot]

Thanks to all.

 

Stripped it out and fell short of removing brushes to clean thoroughly, there seem to be soldered adjoining parts preventing removal without de-soldering (probably no such word). Got close enough to determine that it all looks clean and healthy. I'll try refitting next weekend but in the event of it still being a problem, does anyone know of someone near Worcester who could inspect / service it?

[pistnbroke]

never seen an alternator where you needed soldering to get the brushes/brushbox out ..the fact that its flickering does indicate a brush problem provided all connections are tight and not vibrating

Edited February 28, 2011 by pistnbroke

[Ynot]

never seen an alternator where you needed soldering to get the brushes/brushbox out ..the fact that its flickering does indicate a brush problem provided all connections are tight and not vibrating

Yes I was surprised also, but put it down to it being necessary because of the vibration. It is possible that the connecting parts are severely clamped / crimped together, but I wasn't about to use too much force to seperate them in case I broke something.

[Ynot]

Yes I was surprised also, but put it down to it being necessary because of the vibration. It is possible that the connecting parts are severely clamped / crimped together, but I wasn't about to use too much force to seperate them in case I broke something.

Took Gibbo's advice and cleaned the brush set and rotor as best I could without full disassembly and have now refitted it on the boat. No red lights showing so I hope that's an end to it. Thanks again to all who advised.

[Giggetty]

On a related issue, why no output on my alternator w (tachometer) screw terminal?

 

I know that this should be when running 7-10v AC.

 

The alternator came with the boat two years ago and was said then to have been reconditioned. Do

technicians when they do this inadvertently disrupt the phase winding connection?

[Tony Brooks]

On a related issue, why no output on my alternator w (tachometer) screw terminal?

 

I know that this should be when running 7-10v AC.

 

The alternator came with the boat two years ago and was said then to have been reconditioned. Do

technicians when they do this inadvertently disrupt the phase winding connection?

 

 

Possibly a dry solder joint or a faulty diode. With one one phase not working you may well still get the batteries charging to a degree & the warning lamp going out.

[Sir Nibble]

On a related issue, why no output on my alternator w (tachometer) screw terminal?

 

I know that this should be when running 7-10v AC.

 

The alternator came with the boat two years ago and was said then to have been reconditioned. Do

technicians when they do this inadvertently disrupt the phase winding connection?

Alternator type?

[Giggetty]

Alternator type?

Unidentifiable, there being no manufacturer's name on the casing. However, I was told by the seller that it was 'of Dutch origin'.

 

There is an external fan, and a plastic end-cover, marked B, W, B1, corresponding to screw terminals, and two blade connectors, one marked F (as I remember-it is in a rather inaccessible place) and another diametrically opposite with seemingly identical function-for charging lamp. The negative return is the casing, so presumably not a marine type. B1 is not connected.

 

Bukh engines of this series were originally equipped with SEV Marechal (Motorola) alternators type 14/35A (workshop manual). The handbook states a 50A device, though. From the illustration in both , mine seems to have a much smaller pulley.

 

I shall have to remove it in order to open it up, I guess. I shall photograph it for the interest of this forum shortly.

[Tony Brooks]

Unidentifiable, there being no manufacturer's name on the casing. However, I was told by the seller that it was 'of Dutch origin'.

 

There is an external fan, and a plastic end-cover, marked B, W, B1, corresponding to screw terminals, and two blade connectors, one marked F (as I remember-it is in a rather inaccessible place) and another diametrically opposite with seemingly identical function-for charging lamp. The negative return is the casing, so presumably not a marine type. B1 is not connected.

 

Bukh engines of this series were originally equipped with SEV Marechal (Motorola) alternators type 14/35A (workshop manual). The handbook states a 50A device, though. From the illustration in both , mine seems to have a much smaller pulley.

 

I shall have to remove it in order to open it up, I guess. I shall photograph it for the interest of this forum shortly.

 

 

FWIW my Bukh has a 60 amp Paris-Rhone (Valeo) alternator and TW Marine give me the impression that this was standard on the DV36 when my engine was new. However I can not recall seeing those terminal designations, but then I was probably not taking too much notice.

[Sir Nibble]

If this is (as could well be) a Paris Rhone unit, then the terminals have a crucial series of different thickness spacers UNDER the rectifier. Often these are put back wrongly or replaced with unsuitable washers. The W terminal picks up from under the rectifier and wrong spacers under the other terminals hold the rectifier too high and prevent contact.

[Tony Brooks]

If this is (as could well be) a Paris Rhone unit, then the terminals have a crucial series of different thickness spacers UNDER the rectifier. Often these are put back wrongly or replaced with unsuitable washers. The W terminal picks up from under the rectifier and wrong spacers under the other terminals hold the rectifier too high and prevent contact.

 

 

Thanks for that. Great information - I could just see myself doing that.

[Sir Nibble]

Thanks for that. Great information - I could just see myself doing that.

How do you think I found out

[Sir Nibble]

That B1 terminal, I'm betting that's a mistake and it's 61, yes?

[Giggetty]

That B1 terminal, I'm betting that's a mistake and it's 61, yes?

Could be, but some alternators do have a B1 terminal.

 

I'll let you know more when I have the thing out of the boat tomorrow.

 

I'll also tell the autoelectrics people about the washer issue-very interesting, that.

[Ynot]

Back to the original post, I'm afraid I spoke too soon 'cos the flickering warning light is back.

 

Gibbo mentioned that it would have been better if I had not removed the alternator so that tests could be carried out. As it is now reinstated, could you let me know what exactly I should be checking. I have a multimeter but not a load tester beyond 10 amps.

 

Thanks.

[Sir Nibble]

Back to the original post, I'm afraid I spoke too soon 'cos the flickering warning light is back.

 

Gibbo mentioned that it would have been better if I had not removed the alternator so that tests could be carried out. As it is now reinstated, could you let me know what exactly I should be checking. I have a multimeter but not a load tester beyond 10 amps.

 

Thanks.

Enormously difficult I am afraid without knowing what type of machine we are dealing with, a photo would be most helpful.

Do look carefully to see if there is any fluctuation in the engine instruments or flickering of the instrument backlighting concurrent with the alternator lamp.