[JimD]

I must admit I've never looked but I assume our cars have the normal switch in the door jamb. I would look at them and be sure the switch has not come loose. If the projection of the little plunger is reduced by loose screws, the switch may not close creating the symptoms you describe.

But batteries can fail in 2 years too. I agree that batteries cause the car to do absolutely stupid things. When my alternator quit, the windshield wipers came on and would not go off. Same thing happened when my wife's battery catastropically failed. My battery is over 9 years old. My wife's failed in just over 4. The life is not very dependable. BMWs absolutely freak out over low voltage. Your 14V measurement is not the battery, it is the alternator. The battery cannot produce over 14V. I do not know what cranking voltage should be but your voltage without a large load should be about 13.2V. If it is less than that, it either needs charged or replaced. "Bad" batteries are less than 13V.