I did what you said, Covkid, and lay across the engine bay to feel for loose wires...i couldn't feel any that were loose. From there, I didn't know what to do, so I caved in and phone the AA (I have homestart).
Within 30 minutes they came out - he said that all wires were present and not loose. He checked the battery and said it was slightly low, but thats probably because I hadn't started it for 2 weeks.
He commented that it was strange that the van wouldn't start in P but only in N.
He got it started almost immediately but commented that it sounded slightly loud and that there was a bit of a 'jam' when starting it. He thought that maybe the excessive rain and wind we'd had might have caused the starter motor to rust slightly and its jarring somewhere when it starts. It sounded like it was jarring.
I took it on a 30 minute run to charge the battery and it started when I stopped the engine, but it's definitely not sounding right.
I think back to the garage tomorrow...but not the same garage I used before :-/
Thanks for all your help - I've learnt a bit about starter motors, so that's a good thing
