Solved it, a bit embarrassing really, after your reply i gave them a proper look, a combination of never really paying attention to them, conflicting headlight unit configurations and an Amazon replacement W5W that said canbus error free, that evidently were not had me looking at the high beams thinking the dipped beams had gone, couple that with the fact that the dipped beams don't really look bright enough in the sun, and hey presto, I've convinced myself the high beams are dual filament, the cable I tested didn't have voltage to -ve, because it was the -ve....
Thanks everyone for the replies, and sorry for inadvertently wasting your time....