When I plug in the charger nothing happens, should it? When I connect a battery the display turns on but when I press start the message "ERR" comes up. I am in the UK, hence, I am using a converter which converts to American plugs and 120v. I think no Electrisity is getting through, so I will try replacing the fuse but anyone else have any idea's?

try using it with your auto battery with the attached alligator clips. That would tell you if it is functioning or not.

Is your power adaptor working properly? Does it work with some other appliance, like a lamp or something? Or do you have a meter to test it?

When you hook the charger up to the power without a battery attached the display should appear. As I said previously, test it with your 12 volt car battery with the alligator clips.