You could have a couple of problems here. You battery may be low due to the belt breaking and then not keeping the battery charge up, especially if the belt isn't tight. If the idler is jumping check on this site for belt routing diagram and make sue yours is correctlyrouted. Then make sure the pulley is tight as it should n't be jumping around. You may need another belt tensioner. That may be worn. If you don't fix it you'll be replacing our serpentine belt once more.