Missing alternator???

[raz88 96]

Hi all

 

I have a 2 cyl 13hp Lombardini engine in my boat. I think it's a model MO502.

 

As a result of some charging issues I decided to locate the alternator and look for signs of trouble, and potentially take it off and in to a suitably equipped person to try and diagnose my issue as I suspect dodgy regulator.

 

Problem is, I can't find the alternator! I've looked at both ends of the motor and the only thing that appears to run off it is my fridge compressor at the front, and the gearbox going to my prop shaft at the back. The manual I have for the motor shows it being on the front of the engine run off a belt on the crank pulley, but on my engine there is just a gap there and the only belt is running the fridge compressor.

 

The charging issue I have is that the batteries charge for a while after starting the engine then when I check back half an hour later they've stopped charging. So there's definitely a charging device of some nature there because I see 15v or so immediately after starting the engine instead of the normal 12.

 

I'm hoping someone on here may have come across one of these engines before and know about some trickery that may have been done to hide the alternator and where it might be (wondering if perhaps it's hidden under a cover somewhere and there's somewhere a belt can be driven internally or similar)?

 

I seem to remember once hearing years ago that someone had developed technology to enable a starter motor to be used as an alternator as well but I don't know if this ever got produced and it seems far too high tech for my (basic little) engine.

 

Any ideas?

[Farrari 4]

Page 40 of the service manual shows an expanded diagram of the starter motor and alternator.

 

http://service.lombardinigroup.it/documents/Manuali%20Officina/English/Work%20Shop%20Manual%20GR%2012%20matr%201-5302-460.pdf

 

Hope this helps.

[raz88 96]

Thanks Steve.

 

That manual is for a different engine to mine, but if the alternator on mine is shaped like that so that it could be built into the fan on an Air-cooled engine, then it's quite possible that it's installed somewhere clever that I haven't looked as I was looking for an alternator shaped like a traditional car one.

 

Will go back and have a look being now mindful of the fact that it could be that shape and see what I can find.

[Grinna 2]

The workshop manual shows two wiring diagrams for your engine ... one with an external alternator and one with an internal.

 

I'm guessing you've got the internal alternator version.

 

go here http://service.lombardinigroup.it/engli ... dex_gb.htm

 

and click on the LDW502 on the left

 

and go to page 18 (page 17 shows the external aternator.

 

ETA it looks like the internal alternator sits on the front of the engine where the cooling fan would bolt onto (in front of the water pump?)

[raz88 96]

Thanks Grinna, it is indeed under a cover in the area where the fan would normally attach.

 

Cheers