Alternator Advice Needed

[Pete the Cat]

I used a 105 amp high output alternator (from Ample Power) with my 42hp Westerbeke coupled with a Ample Power Smart Regulator for 15 years to charge my golf cart batteries (ran my crummy Adler Barbour reefer for two years in the tropics) with no problems--even with a small v belt. I am repowering with a Yanmar 3JH4 and it has an 80 amp internally controlled Hitachi alternator. I was going to get a alternator guy to change the stock alternator from N to P (from internal to external) so I could use the same regulator, but he says he does not recommend this. Any thoughts on this or alternatives??

[donradcliffe]

Find another alternator guy.

[georgelewisray]

Talk to another alternator guy. No technical reason I am aware of that you can't break into the alternator and disconnect the field wire from the internal regulator and hook it to whatever you like. However, no telling about the physical/mechanical details of the conversion.

[Alan Wheeler]

from N to P (from internal to external)

N and P is the polarity. It is not stating internal or external. Both polarities can be made external.
But as to the Alternator, why not remove the original 105A from the old engine and fit it to the new and keep the regulator as well. You will miss the power the old one provided.

[DeepFrz]

There is a thread on here someplace with the instructions on how to modify the Hitachi alternator. Search around here or the web and you should be able to find it.

Or follow this link

http://www.cruisersforum.com/forums/...ator-7620.html

[Stenn]

Originally Posted by Pete the Cat

I used a 105 amp high output alternator (from Ample Power) with my 42hp Westerbeke coupled with a Ample Power Smart Regulator for 15 years to charge my golf cart batteries (ran my crummy Adler Barbour reefer for two years in the tropics) with no problems--even with a small v belt. I am repowering with a Yanmar 3JH4 and it has an 80 amp internally controlled Hitachi alternator. I was going to get a alternator guy to change the stock alternator from N to P (from internal to external) so I could use the same regulator, but he says he does not recommend this. Any thoughts on this or alternatives??

Did your alternator guy say WHY he didn't recommend this?

My local guy built me a standard Delco 100 amp alternator to put on my Universal 5411, after I brought him the old, dead Motorola 55 amp unit to be rebuilt. He said a primary thing to keep in mind when cruising is "how common is the unit," i.e. if you're cruising to unknown territory and have a problem with the alternator, you can take this standard Delco to any auto electric shop and they'll fix or replace it cheap. But as soon as you take them something you pulled off a boat engine, you get this dumb look from them, and they tell you they can't help you.

So maybe he's thinking since 99% of alternators today are internally regulated, sticking with something that doesn't throw your local shop a curve ball might be easier to support in the long run? A lot of these guys are not exactly brain surgeons