thanks found it short circuit, although main fuse looked ok changed that as well, back on now:blob8:My first guess would be that when you connected the Optimate lead you accidentally disconnected one of the two main leads to the battery (+ or -). If that's the only thing you changed then that's the first place to look. If that seems OK, check whether you have power to the main fuse. When you checked it, how did you check it? Replacing it with a known good one or just visually? Take the fuse out and check with a meter that there's power to one of the connectors (by checking both it doesn't matter if you can't see which side the power comes into).