haven't purchased a test light yet but i powered up the fan, earthing to the fan earth and it works no probs. obviously no power to it for some reason.

I changed neutral safety switch again, no change.

put the harness clip back on to bulk head, no change

replaced all fuses, cleaned contacts and checked there was 12V to both sides, all OK

I did notice that when I put earth on starter and positive on starter i got 12V odd. on my old mans WB i got -12V??????