Battery charging problem

[paul3102]

I have a 2001 225 OX66 and batteries not charging, actually they are discharging. Put new batteries in and terminal connections are perfect. When started my gauge reads 12 at idle and within a few minutes slowly drops to the low 11's, if I rev to 1500 rpm voltage doesnt increase. If I turn anything on the reading drops below 11 V. The Marina mechanic has looked at it twice and is stymied. I'm thinking the recitifier/regulator may be a candidate for replacement.
The motor runs fine even at full throttle, though the voltage doesnt increase. I measured between the terminals and was reading about .4 V less than my gauge at idle. Normally it has run from 13-14 V. Any ideas

[rodbolt17]

either the stator wingings failed,the stator to rectifier connection failed or at least 1/2 the recgulator failed or a fuse is bad.
test the isolator wire for charging.
that setup has a battery isolator built into the regulator.
its for charging a seperate battery other than the one the engine is on.
if it still has an output,use it.

[paul3102]

what are wingings

[rodbolt17]

its how you spell windings with a cat in my lap eating up 1/2 my typing speed/skill.
however as a master tech for Yamaha outboards since 2006, I can tell you to find a real technician as the OX66 has about the most basic simple charging system of all of the V6 motors.

[paul3102]

Thanks for the information