Ok, this is an interesting problem. The battery acts flat when the hood is closed. When I open the hood from inside but leave hood partially closed, it still acts flat. As soon as I pop the hood, it cranks. Anybody got an idea?
Seems quite logical also something possibly pressing on the fuse box,As you've replaced all the cables I would suspect that you got one of them wrong. It could be that something is being pressed down when the bonnet is shut and making a poor connection, open the bonnet and it is no longer being pushed about and the connection returns.