This just pinged up on my email so thought I'd reply and see if I can offer some help! It's been a while (and I've actually sold my focus since) but I did manage to fix this. In my case it turned out to be a fuse (32) which had blown in such a way that it wasn't obvious so might be worth double checking each fuse individually?

Alternatively while I was looking to solve the problem I did read a lot about the possibility of a break in the wires where the loom passes through to the boot of the car (little rubber casing in the top of of the boot)

Hope this helps? Remember how infuriating this was at the time!