Okay I've changed the loom, the reg/rec, lower radiator and fan, replaced the carbs with a nice clean set, and the bike is running better than ever... however the fan doesn't come on it works if I earth the wire that connects to the switch against the frame so I replaced the switch (the switch in the side of the rad) and it still doesn't work, is the lower rad earthed to anything? as, if I try and earth it against the rad it won't work either.

I really am confused now!

Is it getting hot enough to turn on??

I think the fan turns on with a water temp somewhere around 104C.

Got round to the H, so any hotter and i'd worried about the internal damage. I have another NC30 and that fan comes on at around 3/4 way round the dial.

From memory most of mine have turned on when the temp needle is in the red zone.

I wouldn't trust the accuracy of the standard gauge very much.

Nope with you on the not trusting the gauges but the bike got very unhappy and stalled, then took a while to get started again. 99% sure the fan is not kicking in.

Yeah sounds like your rad isnt earthed ( i think the proper earth is to one of the fan bolts), just run a wire from the engine/ frame to the rad.
Cheers
Ian

Lovely thanks i'll give that a shot tomorrow!