Sorry George but if I've understood your suggestion correctly you do NOT want to be shorting any part of the ignition to warning light circuit to earth/chassis. The warning light works on potential difference across its contacts not at all on any direct ground connection. To work as TBM describes it can only be receiving a faulty reverse current.
Richard, no need whatsoever to apologise relative to advising where I might get things wrong...Always pleased to learn, thanks.
I think I understand the illumination of the ign lamp depends upon potential difference, and that there should be none once the alternator is generating voltage..
My thinking on the alternator end of the warning light circuit was once it had been disconnected from the alternator was to then to ground it, was more as an "extra" check o confirm that it`s switched live side of the ign light circuit was not picking up some sort of grounding via the many paths available to it along the lines that Dave suggested i.e. through a failing seat belt diode..
Always greatly appreciate your input Richard.
