Last week my 2011/F was idling in when it stopped. It turns out the alternator belt broke and it overheated. Got a new belt at Napa ($22) and installed it. A two hours exercise of patience as the space is very tight. Everything worked out fine, but my suggestion is to replace the belt regularly. Mine has 500 hours and the belt showed cracks throughout. Could have ended in expensive engine damage which it apparently did not.