Yep it seems this issue has been around for a bit. I mean 4 different wiring options in this thread alone, and of few more in the forums...But it seems to me that the most recommend one is the return ground thru wire shield. As per this diagram...
http://www.aeroelectric.com/articles...tchOptions.pdf
So Dave, I'd
eventually wire it as per the diagram above. No, the double wire shields will not be an issue.( see the switch contact points operation above... Note: R and the ground next to it are jumped together at the terminals, so the diagram is a bit skewed.)
Now that being said...they all try and I believe do achieve the same basic end results. But some with unwanted and possibly
damaging effects. I'll leave the debate about good, best, and better, for another time. Which I think Dave alluded to with his can of worms....
So leaving your wiring as is ....it should still work.
Back to troubleshooting...
First...Is L terminal at the switch REALLY grounding out whilst starting. (Wiring or switch problem)
Secondly... Will the Left mag start the engine
on it's own.
(Mag issue)
I leave it to your expertise on finding the results but if I were asked to recommend something...
For 1) Take out the starter fuse. (no power to the switch, and starter contactor) and check for continuity between L terminal on switch, and ship ground with the switch turned to the start position. Note...engine should not turn over, and I don't believe that any voltage will be present at the terminal with all wiring as is. But perhaps removing L plead from L terminal would be wise. Replace fuse...
For 2) Leave Left mag plead disconnected from terminal L on starter switch, and see if it starts!
Regards,
T.C.