The second picture in the wiki is of the output connector, so for the input side the wiring would be the opposite. Could this be a source of confusion.
Also if you compare the first picture in the wiki with the picture on Rays site, the picture in the wiki shows the +12V GND wiring mirrored on the connectors (as it should be) but the picture on Rays site does not have the wiring mirrored - so it is wrong.
I am still none the wiser as to the correct wiring for these.