G'day Mike Tyler and Norm
One thing I have heard is that the parts manuals don't always bother listing the charging diode .
A single wire with a diode is generally a DC only system. The diode rectifies AC to DC for battery charging .This system is unregulated in that the energy delivered to the battery is totally dependent on engine speed• A red wire with a diode and black wire without a diode is a Dual Circuit system that offers DC for battery charging and AC to power lights•
A single wire feeding an electronic component (regulator/rectifier) is a rectified and regulated system which is less dependent on engine speed than the DC only system• Two wires of the same colour feeding a regulator/rectifier is a rectified and regulated system that offers even more energy.
https://www.briggsandstratton.com/eu/en_gb/support/faqs/browse/charging-system-alternator-test.htmlhttp://web.missouri.edu/~schumacherl/276781SingleCylinderOHV.pdf
Cheers
Max.