Im driving on the motorway earlier today doing about 50mph all of a sudden everything cuts out on me , luckily i manage to get onto the hard shoulder,i turn the key again , nothing , i turn it again then it wants to go but wont , i call out the AA and the guy takes the rocker cover off and says theres no movement in there and it might be something to do with the crank , im totally lost , anyone any ideas please ?