Is this BS?

E

ex-Gladys

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Gladys has a Lancing marinised Fiesta 1.8 diesel. The alternator has gone T.U and is the source of the charging failure at the weekend. The electrician who tested it is now saying that I need a "marinised alternator" which is properly isolated and is happy to charge me significant wonga for one...

So is this bull or not? I've not seen this mentioned in any threads on this august site, and thought I'd ask...

/forums/images/graemlins/confused.gif
 
I think it's bollocks - cant see anything on my alternator which suggests it's marinised ... It's got a gizmo which allows it to produce 2 separate battery feeds, but I'd guess your electrician wont have a clue what that is.

If I had the "opportunity" to replace my alternator, i would not be taking the word of the electrician fixing it... I would want to research the market, ask questions here, and find out waht is truly the best, or cheapest, or most effective, or whatever.

e.g. if it charges a reasonable sized domestic battery bank, I might be thinking of a Balmar, which people here talk about, perhaps along with a management system of some kind.

I hope some will come along and confirm what I'm saying about it being just an ordinary alternator, cause I'm just finding out about this stuff.

Cheers, Richard
 
Go down to your local scrappie & buy a bucketfull of Fiesta alternators by weight for their scrap value. Put them in your shed & use as required as a disposable spare. I bet you could replace them once a season for umpteen years and still be better off.

I would guess that his concern is more to do with corrosion between dissimilar metals than anything else. How wet does your engine get? How much worse is it than under the bonnet of a car? Pay & you MAY get peace of mind, but on the other hand you may not be much better off than getting one from the scrappie.

How long did your current one last? What guarantee is he prepared to offer? I'll bet the former is longer than the latter!!!
 
Marine alternators supposedly are better sealed etc etc. I recently put a new auto alt. on my engine - a few specs of rust from when the engine water pump started dripping and sprayed around the engine compartment, but I could have painted it....

Searush's point about under the engine hood of the car is spot on - do you ever worry about the salt spray from winter gritting being hosed into it at 70mph?
 
its all to do with insulated neg & not using the engine block as neg return.
my marinized Nanni uses the engine /forums/images/graemlins/confused.gif
my Perkie 4108 had insulated rtn but copper pipes to the ali gearbox cooling /forums/images/graemlins/mad.gif
 
According to Lancing marine price list they do not give the option of insulated electrics for the 1.8. This does not mean they did not do a special.

The give away is that if either of the 2 senders (temp & Pressure) have 1 connection only then the block must be connected to negative. (earth return)

Another clue is if there is a great big black cable to the engine metal then it is earth return.

If no cable and both sensors have 2 terminals then it is harder to tell. Try that for now.

You only need an isolated starter or alternator if the block is isolated from the negative of the batteries.
 
IMHO Searush is spot on! ..... except that down here the 'scrap-yards' went upmarket years ago and now test and label nearly everything. Still, a good working alternator will still only be around £15.

My BUKH engine originally came with a so-called marinised alternator ..... failed as soon as it saw a bit of water spray. When I stripped it the diodes and regulator were assembled as discreet components on an ordinary PC board.

I also think you'd be hard put to find any common small boat diesel where the negative was in fact isolated from the engine itself.

Vic
 
[ QUOTE ]
my Perkie 4108 had insulated rtn but copper pipes to the ali gearbox cooling

[/ QUOTE ]

Would that be a TMP gearbox?
 
Starter on a 4.108 without a solenoid takes about 30 minutes to marinise. Alternators are much harder, if not impossible, depending on how the diode block and the regulator are mounted.
 
I'm with all the rest. Bang a recon car alternator on and keep a scrappy on board as a spare. ( mount it first to make sure it's a goer)
 
Just ask yourself how long the existing one has worked for. If it is a marinised Ford then it will be almost certainly negatively "earthed" to the engine. I have both a Vetus engine (which is a marinised Mitsubishi) and a Volvo on my boat and they are both negatively earthed to the engine block. The only difference in the so called "marine" alternators seems to be that the mounts are insulated from the engine block (anyone know different?) However if your engine block is negatively bonded to the battery and does not have an insulated starter motor negative (which it won't have) you will need to earth the negative to the engine block anyway so IMHO go to an automotive dealer and buy one.
 
I recently bought a 70 amp marine alternator from an Ebay seller for not many sovs (under £60 by memory) after finding there was no charge from the T90. I sent a wiring diagram and a page out of the engine manual to the Ebay man to identify the unit.
When I went to fit the new unit I found the old one was an isolated earth unit which was obviously a retro fit as the manual specified a case-to-engine earth.
If my marine alternator is "standard" earth I don't see the merit in paying a lot more money for an isolated earth unit which will need new cabling.
 
agree with the above cheap solutions. I'm in the process of swapping out my old "E-type Jag" lucas on a 4108 for a higher power bosch from an audi in the scrappie. The original is isolated return, and the "new" one has now been modified by insulating the negative screw from the body, as well as adding wire for the smart controller. It's good to take a scrappy alternator apart before fitting as you can lube the bearings, check the brush length etc. Make sure you get the same chassis-type (fitting) as the original and that the pulley is not offset or anything silly like that. A smaller pulley will probably help if you're moving alt from a high revving petrol car to a slow revving marine diesel. There's no black magic involved!
 
The existing alternator was new with the engine in 1996, so I'm sticking with that.

The XLD is available with isolation, but mine isn't so I ain't going down that route and having to put onding in on other stuff.

I am contemplating in the future using something like a Balmar with smart controller to deal with my 3x75AGM domestics and 1x75 AGM engine in the future, but not yet
 
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