Fords vans are a nightmare of bad electricals because the plugs in the interior are not marine grade.

So don't close up any wires or render them inaccessible.

You need to have provisions there for rewiring -- from the word go.

Also think same when you do your electricals.

I wired mine for 4 circuits.. 2 to way back (provisions for generator), and 2 going to side beside side door.

Also did 12V wire --- used a ribbon cable with about 6 conductors doubled up..

Be sure you have provisions for things like coax (if you need it for TV), and also ethernet (if you need it).

Audio cable.. optical cable.. etc.