1 phase is down possibly.

Vehicle alternator,3 phase,3 seperate coils out of phase if that makes sense.

im guessing that the pole iv checked that didnt have a reading is correct. If itscoming out the generator stator it will be in AC. So its alternating current maybe the pin with no output was that alternating. If it were DC it would be each pin with output. Or am i wrong. Still think the rectifier / regulator maybe faulty

Not sure about stator driven charging but cars etc "alternate " and rectify to dc with voltage regulator, daft question what battery are you using and is it possible to use a car battery,not sure if bike charging system would have capacity for large car battery.

using odyssey 625 battery, brand new as specced by westfield. It does work ok, just something has failed. Just not sure of the correct way to check the stator.