The "W" terminal on those alternators is a direct tap off the stator that gives an unrectified alternating current feed used by the tachometer to figure out how fast the alternator, and hence the engine, is turning.
The alternator regulators I am familiar with do not use this feed to do anything other than generate their own tachometer feed signal, and it can be left connected as it is to avoid more rewiring. I'll hedge that by saying I am not intimately familiar with the Mastervolt regulators...
---In amelyachtowners@..., <svgarulfo@...> wrote :
Has anyone gone through the exercise of upgrading the MasterVolt Alpha Pro alternator regulator from the version installed by Amel to the MasterBus compatible version (Alpha Pro 2, aka Alpha Pro MB).
They are very similar but the newer one, being MasterBus compatible, is easier to monitor and configure.
Amel's wiring on the 54 involves a couple a relays and a mystery box that I believe is a static 12/24v converter and I'd like to gain confidence about the setup before doing the transplant.
Attached is a badly drawn diagram of what I believe the connections are.
I'm confused about the purple wire connected to the W pole of the alternator, especially because the new version of the regulator has an extra connection point that is meant to be wired directly to that W pole.
Any tips greatly appreciated, as always.
Amel 54 #122
Cap d'Agde, France