Originally Posted by svstrider
Thanks for your advice. Yes, I am sure it is connected to the starter battery which is right next to the engine. I have checked all connections and redone the excitation wire from the external regulator. I did notice that the Xantrex ext reg directions say to connect the duplex blue & white wires to the alternator. As far as I remember, there is only a blue wire going to the alternator. I will have a look early tomorrow as it is now too damm hot in Thailand
after 9 am to do any engine work.
Why is it directly connected to a start battery? Is this alt intended for just charging
a starting battery? A 100A alt for a battery bank that will usually take less than a few amps seems a bit of overkill.
The white wire is the stator or AC tap wire intended for driving an alternator sensed tachometer. We don't know what engine you have and you may not have an alt sensed tach. When installing aftermarket alternators, on Yanmar's for example, most don't have the terminal to drive the "dash light"...
You saw 3A and this would indicate that the alt is working. What was the voltage when you saw the 3A? If the batteries are full, and not accepting much current
, you won't see much in the way of current
output . You likely missed the brief in-rush of current before it settled back to the 3A....
Which regulator? Where is the "voltage sense wire" wired to?
The blue wire is your field wire for the alternator. Without this connected it will not work at all.
Be sure your alternator has the same size neg wire as the positive wire you are using for the alts B+ or output. So, if you are running a 2GA positive wire then you also need a 2GA negative wire.