2000 Dodge Caravan Key will not turn in lock

Other then a mechanical malfuntion with the key cylinder it may have a problem with the shift interlock solenoid, a safety item that works in a circuit with the stop lamp switch on the brake pedal, the powertrain control module, and the solenoid itself in the column. A 10 amp fuse inside, number 2 may be blown or you'll need to use a DRBIII to diagnose and repair it. Your foot must be on that pedal. Hope this gives you some relief. Thanks