Part identification - please help

Actionmat

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I need to identify the burnt out component in the bottom middle of the box(close up first pic)in order to track down a new part. I'm afraid to say that I don't even know what it is or what it does, but I assume it's the reason that my alternator light on the dash is coming on and off while the needle flickers then returns to zero amps.
I ordered a new regulator and them noticed that this bit was knackered.
It's a CAV alternator on an old Perkins 4107
Any help appreciated thanks....

View attachment 52702
View attachment 52703
 
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Plevier

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Isn't that a regulator for an old DC generator (dynamo), not an alternator, and the burned item is the cutout?
Can't you get a complete electronic replacement?
The cct is helpfully on the box lid but I can't quite decipher it in your photo - can you link to a higher res one?
 
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Simonpk

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That is really old tech'. Scrap the lot and fit a new alternator, you will be amazed at the difference it makes.

My thoughts exactly, It'll probably be easier to source new than find those old components.
I think Noah was the last guy to have one of those:playful:
 

Actionmat

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Isn't that a regulator for an old DC generator (dynamo), not an alternator, and the burned item is the cutout?
Can't you get a complete electronic replacement?
The cct is helpfully on the box lid but I can't quite decipher it in your photo - can you link to a higher res one?

If I could afford to I'd scrap it, but it's not on the engine that powers the house batteries and it's worked well up until now..
View attachment 52705
 

30boat

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The minute I looked at the picture I remembered the regulator on my 1954 Norton Dominator.You can get electronic regulators for dynamos these days .
An alternator would be easier and more effective though.You can get one from a scrapyard with a built in regulator rectifier.
http://www.dynamoregulators.com/
 
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Plevier

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If I could afford to I'd scrap it, but it's not on the engine that powers the house batteries and it's worked well up until now..
View attachment 52705

The cct seems to be drawn to match the physical layout in which case the bit you have highlighted would appear to be the coil shown in the warning light circuit. In your photo it looked to me as though it had contacts on the end but apparently not.
If you really have to rescue this I suspect you will have to make a new coil yourself to match the burned one. It's probably not very critical, you might just have shorted turns, you may be able to clean it up and lacquer or silicone it.
Have to admit I can't quite see how it all works, never seen anything quite like it!
Is there a maker's name and type number on the box for the whole assembly?

Oh just seen BlowingOldBoots post - looks as though he can be more help. It is an alternator after all is it? Rather different from present day ones!
 
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VicS

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If I could afford to I'd scrap it, but it's not on the engine that powers the house batteries and it's worked well up until now..
View attachment 52705

So its an alternator anyway but that must have been the first solid state alternator control system Noah installed after he he did away with a dynamo.


I think I'd try bypassing everything in that bottom box, or at least the burnt out coil
 
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Actionmat

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Thanks everyone for your help and advice. I'll try bypassing the coil as suggested and take it from there.

MIL about to join us for a 2 week trip, SWMBO thinks I've sabotaged it on purpose:D
 

Plevier

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Looking at the last drawing in this http://www.solidebolide.nl/downloads/CAV Workshop Manual 24V Alternator.pdf it appears you can use the regulator unit attached directly to the alternator without all the extra gubbins that you have got.

Even better, look at http://www.stationary-engine.co.uk/CAV-Electrical/AltBatt.htm particularly page 9 http://www.stationary-engine.co.uk/CAV-Electrical/CAV99.htm
It appears from there that everything in the part of the box you have problems with is just for RFI suppression and you may well be able to do without it.
The main unit is described on p5 http://www.stationary-engine.co.uk/CAV-Electrical/CAV95.htm
 
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William_H

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It does seem to me that the "burnt out" part is just somewhat damaged by old age and use. It is just a coil with contacts. I would clean up the carbon etc and try to clean the contacts of the coil. Check for failure of insulation and real damage and see how it goes.
In the begining with transistors and diodes over voltage damage was comon as they could not make transistors and diodes with large voltage breakdown rating. Since then huge improvements in semiconductors has produced components able to in many cases withstand high voltage spikes etc. Hence an old alternator may fail from being operated with no load due to spikes of voltage damaging diodes but a newer alternator will be far more resistant.
So it is likely some of those components are to protect the semiconductors in the regulator and alternator. A modern equivalent is more robust so simpler.
good luck olewill
 
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Looking at the last drawing ..... Even better, look at ..... It appears from there that everything in the part of the box you have problems with is just for RFI suppression ...

Thanks for posting the links and the explanations. It has completed the picture for my own system.
 

Plevier

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Thanks for posting the links and the explanations. It has completed the picture for my own system.

Just a chance find. Hope it helps the OP too.
It seems these were used - maybe developed for - a variety of military vehicles. Would explain the heavy duty approach.
 

Actionmat

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It's a great help, thanks very much. You're right about the military, they're common to army Land Rovers, but I can't imagine why they were installed in a leisure boat that was destined for the river.
 
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