In need of help with alternator wiring

[Gjoa14]

Hi you all,
we are in the last stages of a full boat restoration incl. reassembling our Perkins 4.236 engine. Right now I am trying to figure out how to install my two alternators. My idea is to connect one to the service battery and one to the starter battery.

The older one is a Bosch K1 14V 55A, which I would like to connect to the service battery.
The B+ was previously connected to the starter of the engine, and I am unsure if I could go now from B+ straight to the service battery plus.

The new one for the starter battery is from "Kühner" 14V 50A with internal regulator and thats already all info I got & find in the internet . Nevertheless a local mechanic confirmed that it is suitable for the engine.

Especially the new alternator makes it really difficult for me (with medium electrical knowledge) to do the wires as there are almost no descriptions on it.

Instead of writing down all my guesses I am hoping that for someone else this is all pretty straight forward

Thanks already for any reply & help! Best wishes, Marlene

[jimbunyard]

For the most accurate information, we'd need to know part numbers of the alternators.

Generally speaking, no problem hooking the Bosch directly to the battery; that is essentially the way it is wired at the starter. Make sure the wire is sufficiently large to carry the current, probably 8 or 10 gauge is good for relatively short distances. A ground wire of the same size directly attached to the ground point on the alternator or the alternator frame is also necessary.

How the fields are excited will determine the characteristics of wiring those circuits, if needed; a common method is to interrupt the circuit at either the on/off switch or 'I' terminal of the start switch.

If you have a tach and it operates off the alternator, again, the alternator design dictates the wiring (and suitability), so a p/n is needed.