[tv195]

Hi, I was wondering if the regulator in my alternator (westerbeke 12V 50amp) on my M25XPB has a sense wire
which should be connected to the positive of the battery?
It seems there is no such wire on my boat, so I was wondering how can the regulator sense the battery state then?
Thank you so much,
Feliz navidad,
Chris

 

[mitiempo]

It senses the voltage at the alternator itself.

 

[christian.hess]

yup, built in...

on bad thing about these aletrnators is sometimes getting a replacement regulator cap while cruising can be a nightmare so sometimes having a spare truck or car alternator that you can hardwire to the batteries on some engines works as a great backup

yanmar has the same type...

 

[tv195]

Thank you guys.
So I am still trying to understand the electrical system on board and how the alternator fits in. The wiring of my battery switch (see below) has only one positive large diameter wire (2 AWG) running to the engine. So could it be that this wire is used to start the engine and after that to sense and charge the batteries from the alternator (green dotted line). Thanks a lot for your input.
-Chris

 

[mitiempo]

The alternator charges the batteries through the start cable. This is normal on many engines, not the best way but the least expensive. The starter is already connected to the batteries by heavy cable through the main switch. The alternator senses internally.

 

[tv195]

Great thank you, that explains a lot!
Happy holidays,
Chris