Marine alternator

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Cobra25

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The alternator has packed up and we are told a new one is necessary. YANMAR = £300!!

We have found non-Yanmar for £170. Does anybody have any idea where to go for a cheaper one.

We are told we must have a marine alternator beacause it has an insulated earth cable.

As we do not wish to cause a fire or not comply with best advice we are going to get a marine unit.

TIA
 
Who said you must have marine ??

Why are so many boats going around with bog std alternators then ...

Take a Perkins .......... go to Lucas or a scrap yard and pick up replacement of same design ex bus / truck / van .....
 
Take it to your local automotive alternator and starter repair shop and see what they say - usually they can recondition for only a few pounds(as long as they can get the spare parts). I got a Lucas one reconditioned for about £25 but had to wait a week while they got the bits, as insulated return alternators are not standard on cars.
 
I second that ...

Took my alterantor to a service guy ... looked like new after ... plus it worked better than ever I saw !! Cost about a tenner !!
 
Think the only difference is marine altenators have spark protected innards - but if you have a diesel engine then its not needed, i agree with Nigel, either get your current one rebuilt or get a normal one. I have a pair of 4108s (perkins) running normal altenators, and i have not had any problems.
 
I would certainly stay with the insulated alternator, and especially so if all your instrument senders, etc are all also insulated return and/or the alternator is always live onto the battery (ie no isolation switch between the alternator and battery).

As has been suggested, they can normally be reconditioned.

John
 
Agree with Nigel. I have a new alternator in the boot of my car from a Fiesta ST which will be the 2nd Alternator on my Yanmar when I have made the brackets and done the pulleys. If your engine bay corrodes earths to that extent, I'd change the boat!
There is also a marine electrical refurbishment guy in the west somewhere who rewound and refurbished my old BMW D7 alternator for very little. Give the grey cells a bit of time, and I will remember who it is.

It must be said that young Luther and I do like are secret wannabe breakers yard owners.
I at least have the advantage of having worked in one on weekends in my youth.

Jim
 
Mr. Jimdew ....

Having stomped around a few breakers yards in all the goop and oil soaked mud etc. that unique smell of old oil and wet upholstery ........... I can honestly say I have no desire to be a Breakers Yard worker ... owner yes raking in all that money !!

But in truth they are a gold mine to boaters ... gauges for engines, ignition switches - find a dash mounted switch and you're laughing ... alternators, solenoids, starters, you name it .... literally

Battery's - a lot are tested before they go on the shelf to sell ...

Vire engines ..... breakers yard ignition coil - sets you up for coil ignition ....

Gold mines ...
/forums/images/graemlins/smirk.gif
 
Hi cobra25,

We bought an exchange 70amp Lucas alternator for our boat for £25.00. We exchanged a Paris Rhone one from our Bukh set-up. When we left to go long term cruising, we bought another matching Lucas unit as a spare for £45.00. Cost more 'cos there was no exchange. Both units were like new. /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

Still using the original after 9 years and have never fitted the spare!!

CHeers Jerry
 
Re: Mr. Jimdew ....

Our local yard isn't what it used to be.

The muddy field has been tarmac'd no longer can you climb up the piles of cars. Now they are all stacked on giant metal shelving devices and you have to ask for what you want and they'll see if it's on their shelves or see if they have the right car in. In which case you call back a few days later to see if they could strip off what you wanted.

Probably down to some daft regs. but it's put up prices and it's a long time since I went there.

Jim
 
Have just seen the expert who tells us that alternators for marine use are insulated to prevent escape of electricity, which would cause galvanic action on different parts of the boat.

Makes sense I would think as why would they make them differently. £141 instead of the YANMAR £300, hurts but not too much. Maybe worth asking surveyors to check this on future surveys! So many people seem unaware!

Too expensive to repair unfortunately

Ha'pence of tar and all that!

Thanks anyway.
 
Nonsense! He is trying to sell you as £300 quid alternator when you can get one that will do the job just as well for £50

Every boat I have seen has a standard frame earthe alternator. Some to have insuklated return but my boat for example is 35 years on and is still in good shape, despite my best efforts.

He could argue the galvanic point if the alternator and engine were underwater -- literally underwater... but you will not get galvanic action without an electrolyte.

Probably others can lecture with far greater authority than I but to create a cell you need two dis-similar metals immersed in a liquid -- eg copper and aluminium in saltwater.

Copper and aluminum in air do nothing except oxidise individually.

Attach a piece of copper wire at the end of aluminium electrode (with the copper above the level of the liquid and nothing will happen to that copper either.

Now if your alternator is under water then well you need to look for a new boat and a call to teh insurance company might be wise!
 
Totally agree!! This is absolute bull***t from the 'expert'!! You can use perfectly ordinary 'car type' alternators on a boat without any such problem. As I mentioned in my earlier post, a fully reconned (like new) Lucas alternator (and there were many other makes) was instantly available from our local specialist alternator/starter motor shop at a fraction of these so-called 'marine' jobs.

So don't be conned Cobra25, if your unit can't be economicaly repaired (get a quote) go and get an exchange/reconned unit from a specialist. It'll serve you just as well.

Out of interest, I was so astonished by the low price that I immediately took it round the corner to a main Lucas company and got them to test it. Perfect - and still is!!

CHeers Jerry
 
Only basic differance between standard and marine alternators is, stailess steel fasteners and painted/treated alluminium casting to stop or limit corrosion. Operation and options are common between the two.


Brian
 
if you have an aluminium boat, you must use an isolated alternator. All other boats can use a standard alternator.

Many years ago, "marine" alternators had one difference to ordinary alternators: an inbuild thermostat, switching it off, if it got too hot. I doubt, that this is still the case.

Peter
 
Can I suggest you give the guys at Adverc a call and ask their advice on a new alternator. Although best known for Battery Management Systems, they also sell alternators and I actually bought one from them some few years ago. It was a 90amp model, well specced and cost around £150 if i remember corectly. Although I no longer own the boat in question I do know its still going strong with no problems.
 
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