You know since you can move the cable and it starts, it almost sounds like a build up of corrosion possibly under your negative cable or inside the cable itself. Disconnect the batter Negative cable first. See if the posts on the battery are corroded, cables too. If that works great! if not, I have had to cut the end off of one of my cable before and replace just the end. See if there is any corrosion in the cable itself. If so, replace it or replace the entire cable itself if you feel comfortable doing that. If you do just the end clamp, get some cable grease from your local parts store. Disconnect the battery, negative cable first. Cut off the suspect cable end. Strip back the insulation only far enough to go into the new clamp hold down. soak the end of the cable in warm water with baking soda until it stops fizzing. Blow the water out of the end and spread the strands into a fan shape. Brush them with a clean wire brush. Apply the terminal grease onto the strands. Twist them back together and attach the clamp. Connect your battery cables positive first. See if that was your problem. Hope this helps