Alternator

[paulj]

Ray
Was this the alternator you installed.......http://www.marinepartssource.com/newdetails.asp?pnumber=AR60050&mfg=Arco Auto %26 Marine&mfgno=60050&desc=55 Amp 12 Volt Mando Alternator

paulj

 

[KZW]

That is the drop in replacement for the OEM alternator - the one that is installed on my boat.

 

[JK_Boston_Catalina310]

Here is another option. https://www.amazon.com/gp/aw/d/B00KGIBD5W/ref=yo_ii_img?ie=UTF8&psc=1#nav-search-keywords

We carried this as a spare. Swapped it out back in the Bahamas when I thought I was having some issues with our old one. Turns out it was a battery issue, not a alternator issue. I have been running this one since, about 5 months now. I see 45-50 amps from it. I do have my alternator wired directly to the primary bank and I have a ground wire on the alternator, not relying on case grounding.

 

[Long Story]

I just replaced an alternator this weekend also, it must be time for these to start failing. Lucky have a well know place in Green Bay WI that rebuilds and builds up units. I ended up with a replacement (95 amp see photos) and my original 40 amp rebuilt to put out 60 amps. Only problem was that the 95 amp is a larger case and needed a different belt and bracket. (see Photos) Now the big question, as I have not opened up the lower panel at the wheel yet. How do you calibrate the tachometer as it is now off on it's readings from the alternator output.

Thanks
Russ

 

[LeslieTroyer]

There is a calibration screw on the back of the tach -- shoot the engine with a optical tach and match settings. Harbor freight has them for about $30 - or you international org may have them to borrow (I know the C36/37 org loans them) I have my own.

Les

 

[Long Story]

Thanks Les,
Straight forward enough, the only simple part of this simple project. I found a local auto parts store that will rent me one for $15 for the weekend... not so bad.
Russ

 

[rpwillia]

Paul, et al, I did replace my OEM Mando regulator with a Mercruiser one. The dirty little secret is Mando is the oem for Mercruiser and a bunch of others. I was having problems with mine and no one could tell me if the alternator was good or bad but it was only like $85 for the Mercruiser that was in stock and it was $45 for the electronics that had to be ordered with shipping. Pretty much a no brainer. Guy at the store sez "this should fit". Got it home and had a good laugh as they were exactly identical down to every little screw and connector.

 

[paulj]

My question is at what rpm is required to put out the amps specified by Mfg of alternater.

paulj

 

[JK_Boston_Catalina310]

My question is at what rpm is required to put out the amps specified by Mfg of alternater.

paulj

Before we went to the dark side and got a Honda generator and added 300 watts of solar for a total of 500 watts, we were running our engine a lot for battery charging. We found we got about 35-40 amps at 1,200 RPM. That was from a 55 amp alternator wired directly to the house bank and a good ground wire to a grounding buss. Measurements were from our Victorn battery monitor.

 

[Long Story]

I watched them bench test my new one and it is putting out 80 amps at 1200 and 90 amps at 2200.... I don't know if I would ever get to the point of pulling the full 95 amps out of it.

 

[rpwillia]

I seem to remember Maine Sail stating that you will never truly get 55 amps out of a 55 amp alternator (or something like that) so it looks like you guys are pretty much on target.

 

[rpwillia]

Just sayin'
https://www.amazon.com/gp/product/B00KGIBD5W/ref=pe_2313400_203819000_em_des

 

[paulj]

Ray..........
" it was $45 for the electronics that had to be ordered with shipping"

What electronics ?
paulj

 

[rpwillia]

Ray..........
" it was $45 for the electronics that had to be ordered with shipping"

What electronics ?
paulj

The Diodes are all in one unit.