" I quoted both emails in this response "
____ Of-course you really mean 'posts', (not "emails" [or PMs]).
" Yes, this connection is correct, but not necessary, and is misleading due to the lack of detail in the alternator depiction. Both coils are isolated electrically from any ground potential "
____ Well-then how can that ground/GND.symbol be electrically "correct" in ANY way ? _ What circuit could there possibly be left to be grounded within the alternator-symbol, if both power-coils are indeed 'floating' and "isolated" ?
" the numbers show that the lighting coil was shorting somewhere inside the windings.it's possible that that lighting-coil was once mistakenly used to power the mag.ignition-system and-so possibly resulted with that power-coil's insulation-coating having become somewhat burnt & weakened
it is obvious that it can't be fixed short of rewinding the coil."
____ So then does that power-coil's wire-coating look very brown & possibly burnt dark ?
(All the lighting-coils I've ever found with reduced resistance-values, were burnt to at-least a dark-brown [if not near black] !)
" As for why the Red-white came out that way, I am not sure,
maybe if it was isolated from ground it would have been the series sum of the two "
____ It seems that either you overlooked my related explanation or didn't grasp it's indicated point (as I expected the likes of Hans to grasp). ...
__ My posted pair of drawings depicting the power-coil's possible ground-connections, display the two possibilities of how the ground-connection might actually be. ...
The left-side version reflects the coil-connections as you've drawn them within your posted drawing, while the right-side version is the only-one which supports the related ohmic value figures (as listed next to your drawing).
In the left-side version, it's obvious that an ohm-meter connected to the red and white wires must read the resistance-valve of the entire coil-winding, (as-if the "series sum"),, however in the right-side version, it's obvious that an ohm-meter connected between the red & white would only measure just the longer-length (of the entire coil-winding) !
So providing that the related ohmic-figures are all correct, they then must indicate that the only possible deduction is that the connection-arrangement indicated within the right-side depiction, is the only correct arrangement that collaborates with the stated ohm-figures ! _ So in like-kind, the found ohmic-values allow for only the one deduction which indicates that the right-side connection-arrangement must be the CORRECT-one !
__ And that's the bottom-line on this matter.
I've now included labeling on the pair of coil connection-arrangement depictions, which now ought-to make my intended point more apparent.
Enlightening-Cheers,
-Bob