I have been told by the previous owner that it had the wire splices as per this website. I have checked that the PGM O/B to Bl/W has been done. Looking at the condition of the GPS lead, it looks like the black sheath has not been cut anywhere (near the connector). I have yet to trace it all the way back to the engine sidecover.
Earthing the neutral wire from the connector gives a reading of 5V.
Battery registers 11.9V; when running a steady 14.4V across the terminals.