I think all you can see before you take it out is the brass bolt head type fitting. If I could upload the pic I'd put it on, but I can't at the moment.
But that link has really helped, thanks for that mate.
I dismantled all the dash today because I thought it was the clocks, because I'd just bought them and put them in, but it wasn't working so I took them out, and they didn't work on the spare set either. Oh well, at least I'm tracking it down slowly.