Connect the main red wire to the spare port next to the thick red wires top right of fuse box on pre 99 vans or to any port marked KL30 on later vans. For an ignition supply use a port marked KL15 (black/yellow wires).
Thank you for you're invaluable advice. The windows in and working fine, however they came with two brassy coloured brackets, I have no idea where these fit they have four bolt holes in them each and look as though they fit on the window somewhere! Any ideas