M20J (early 24-0238 thru 24-0377) charging circuit diagram (isolated)

[bradp]

Hi all, 

I am working through a charging circuit problem.  Hopeful to have it up and running again soon.  Alternator has an open in the armature (thank you O'Reilly auto parts).  New Plane Power installed but no charge state.  We're down to the alternator took out existing 1977 OECO 20082 VR vs internal / external short to ground of the field wire.  Given the VR was all over the place on battery power (3v, 9v, 12v), I'm hoping that the zeftronics plug-n-play unit with the trouble light will either solve or greatly aid in trouble shooting.   For anyone with a similar charging system issue, the zeftronics install manual has an *excellent* trouble shooting / resistance verification guide.  There is also unpublished info about that trouble light blinking frequency (Hz) differentiating between field circuit and power circuit issues that the zeftronic folks were kind enough to share.  

For those who have an early 12-V J model, here is a copy of the charging circuit, isolated from the rest of the unreadable wiring diagram. 

Hope this is helpful,

Brad

Mooney 24-0238 thru 24-0377 charging circuit.pdf