Q: Key turns in ignition tumbler but it gets stuck in the on position and won't start.

Hi there. It is possible that the key lock in the steering column may have broke. This lock is what returns the ignition tumbler back to the rest OFF position. The lock may have broke making the key not move in the tumbler, but also the ignition actuator may have failed causing the functions to not start the engine or turn on the power. If the key will not come out of the ignition switch, I recommend removing your negative battery cable (-) from the battery to prevent the battery from going dead. Then you can try to get the key out of the ignition switch. You may have to remove the steering column and airbag to get the ignition switch out to remove the key. If you need further assistance with your key stuck in the ignition switch, then seek out a professional, such as one from Your Mechanic, to help you.