Alternator choice

[fslane]

I have a Caterpillar 3116 in my 1997 Mainship 350. The alternator is dying/dead.
I'm looking for specs on a new alternator. The 3116 is 325 HP. I have two house bank 8Ds which service house and engine. The generator has its own battery. The bow thruster has its own battery.
Do I just buy an alternator that fits the mount? Manual says that there are 60 and 95 amp configurations.
Ideas? Everyone is closed for the weekend, but I'll call Cat tomorrow.

Sign me "Moored in Beaufort"

Fred

 

[Ski in NC]

An alternator is a machine with lots of parts. Very repairable. Might be just one little widget causing the problem. I know there are a couple of automotive DC equipment shops in MHC/BFT, not sure which would be best.

Take the alt off and go to one of the local shops. They can bench test it and decide if a repair is the right path. May have a replacement on the shelf.

Cat is at the Jarratt Bay facility about ten miles away so not too convenient from BFT. You can dock up there on Adam's creek and walk to Cat from the dock. If you are heading north on the ICW you will go right by it.

 

[firehoser75]

Ski is bang on as usual. It can probably be repaired. Last year, being as my boat was 17 years old and I had no idea of the alternator's history, I took mine in for a preventative rebuild. I travel often in "out of the way" places, so I don't like to take chances.
Just a point of info. You do realize that stock alternators (like mine) do not do a very good job of recharging your batteries?? It will support them while running (eg. necessary while using high draw items like bow thrusters and anchor windlass), and it will put some amps back into low batteries, but it will not put your house bank back to 100% in any time resembling a reasonable time frame (if at all). This is not necessarily a bad thing, as long as you are not relying on the alternator as your "main" recharging source.
If you want your alternator to do a "more complete" job of recharging, then you will need an external regulator at the minimum, temperature sensing, and probably a high output alternator. For me, I went solar and am very happy with it, and my stock alternator.

 

[caltexflanc]

I'm not sure which Beaufort the OP is moored at, but there is sure to be an alternator shop at hand. That needs to be the first stop.
If Beaufort NC, the Carteret Alternator shop on Arendell (the main drag AKA 70E) is good:

https://www.yellowpages.com/morehead-city-nc/mip/carteret-alternator-starter-service-17199374

Probably where Gregory Poole would send it.