Unkle Munkle

Check the connection of the leads to the battery terminal posts in the boot. Mine had broken on the positive terminal (there are two thin metal bands). It is a fiddly assembly and, if the contact/connection is not good enough, then you won't get power to anything.

This happened to me, got a new second-hand positive terminal connector and it's been fine ever since. A new one from Alfa was over £100 as it came with some wiring etc - scary price!