I'm pretty sure that Bill and I put up all the relevant stuff. I did it with a Next Step reg, but basically the wiring will be similar.
The wire you need is the field connection from the alternator, that's what the reg uses to control alternator output.
One caveat on this whole scenario is that you need to realise that the LN 175A alternator is not continuously rated
So, with a 3 stage reg, if your batteries are quite discharged, the reg could command full output from the alternator and if your batteries are able to accept 175A, that's what you'll get... For a while until the alternator burns out!
Solution is to also run the genset and the 100A charger until the charging current gets down to about 100A them turn off the genset.
Best solution is actually to change the alternator to an Idlepro Extreme or. Delstar, both of which can put out around 200A at just above idle.
You don't need to ask how I know this!
Elyse SM 437