How to test and fix 12V Valeo alternator

This time I have a alternator from a Nanni marine diesel, it is the same model as on a lot of Volvo Penta engines.
The charge light is on and the alternator gives no voltage to the batteries so I'll like to find out why it doesn't work.
There is a bunch of videos out there but no video regarding this certain model.
Regarding the voltage regulator it starts charging at 850 rpm. and reach it's max output at 2000 rpm.
A full battery there is being charged has 14-15 Volts and it charges with 5-7 Amps at 2000 rpm.
At 850 rpm idle the voltage must be around 13.5-14 Volts and the charging Amps
must be around 2-3Amp on a near full battery.
If the voltage is over 15 Volts at 2000 rpm. the regulator is faulty.
50A rectifier from ebay : 42 US Dollars

[@asennaydenov6461]

Great video! I've seen this diode dies when the main switch is shutted down while the engine is working.

[@twiper]

The diode can also die if you start up the engine with shore power connected to the boat. And thanks :)

[@yvesrouzieres7543]

Thanks Tino for your videos. This one well explains the different parts of the generator.
Greatings from Pornic, little port of south of Britanny.
I have a Bavaria 30 and i don't miss a video from your north country.

[@davida5072]

Another good detailed and useful video, thanks

[@fernandord4083]

Good video, as usual.Greetings from Alicante

[@finnlavlund4386]

Thanks for yet another good and informative DIY video 👍😉

[@finnlavlund4386]

By the way. Where did you get the new diode? And what is the model named?

[@twiper]

@@finnlavlund4386 I got the new diode at e-bay and the model I have mounted is called : 28T146 ALTERNATOR RECTIFIER VOLVO PENTA, and it was ordered from England. But due to rush I have ordered another one from Germany and this one is of the brand AS-PL and the model is ARC3007 (50A). If you need one I have it on the shelf. The price is around 42 US Dollars. The alternator is born as a 60A but I could only find a 50A diode, the cheapest diodes is only 35A.

[@robertcairns4207]

Vey useful, thanks Tino

[@PaulusPHM]

Nice video thank

[@yachtiebob100]

Thanks Tino, I'm amazed how you work with your left hand all the time while filming with your right!
Have you a link where you obtained the diode pack please.

[@twiper]

www.ebay.de/itm/28T146-ALTERNATOR-RECTIFIER-VOLVO-PENTA-MD2010-MD2020-MD2030-MD2040-TAMD22P/253673156227?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

[@raybelcher]

@@twiper : Thank you very much.

[@vuralmese]

👍

[@SuperSaling]

Could you tell me where the anode goes on a volvo md2020 engine
Thanks
Philip

[@svcgmailsvc313]

Good afternoon, I have an alternator just like the one who would like to test it on the bench. Can you tell me how the calls are made? Thank you

[@gerardoortiz6688]

Thanks for the video, I just have a question, can you test the diode bridge without disconnecting it from the alternator? or is it necessary to remove it?

[@twiper]

You must disconnect the diode bridge to test it

[@gerardoortiz6688]

@@twiper Thank you very much!

[@simonmllerpedersen2735]

Hi
Where do you buy spare parts for this type of alternator?

[@mowzol]

What type of solder? High melting point or will any solder do ?

[@twiper]

I'm not that into soldering, but I'm using normal solder with onboard flux

[@mowzol]

Thanks 👍 I thought that's probably the way forward otherwise their might be a risk of damaging the diode using high temperature so near it. Great clear vids Tino btw 👍

[@jeffbriner4232]

Best for them is to junk them and buy a new one.