Surely the others are just earths.
on a VW there are 5 main BIG fuses on a panel that sits on the battery, does the focus have an extra board under the bonnet that may have popped a Bigger flat bar fuse, I see you have written Engine and central box so assume these have checked out ok.
it is worth getting to the back of the lighter socket and running a new Earth to see if that does anything.
With a test light or tester Ted with one end on and earth and the other end poked in the hole where the fuse plugs in are both of the female parts that accept the fuse legs dead, if there is no love there then there must be another fuse blown.