The dipped headlights (and side lights) randomly come on / flash when I am driving along. I suspect that it could be to do with the light switch but 'wiggling it around' doesn't seem to stop it. I might try to get at the switch but I suspect that it will be sealed. Anyone else had a similar problem?

What year is your van?

It's 2009

You need to contact your local fiat dealer, there was a recall on these vans early 2010 for this spasific reason. It requires a computer-ecu update. You will need to take all available keys with you as the update wipes out the transponder in any key that is not present at the time.

Thanks for that - the van is now due to visit the Fiat dealer to have this fault looked at and a vacuum switch problem as well.

Dealer seemed to fix it at the time but problem still exists. Side and head lights just coming on randomly and main beam going to dip sometimes. Fiat dealer promised to look into the fault further but no further news. I don't think that the Fiat dealer can really be bothered to find or fix the problem.
Any one got any ideas?