09 Taurus cannot start

You should expect the key to return from start position under spring tension. The ignition switch is actuated by it and the switch contains the spring. That is a modular column, take it to the bench for repairs. Expect to need tools and procedure knowledge for security and steering parts. Trouble with parts in the mechanism can be likely just as some trouble you may have with your switch. Turning the key back from start, to run should be all it takes to stop a "starter stays engaged" concern. if it was just the return of the ignition start position in question. You would have to remove it, and start diagnosing it on the bench. This car is newer than the ones I fixed, but, the manual can sometimes be read and or photocopied at your dealer if you cannot pay the expert to do the diagnosis and give an estimate..

Some manuals are donated to libraries as well, but they are beyond 10 years as a rule.

Further, I thought the fasteners could be loose or fell out, or broke somehow, that would be why you had to turn it back so far to get the switch to come out of contact internally. It never hurts to ask the service department for any data they can obtain using your VIN. The service bulletins and recalls can contain info for yours or similar vehicles if there have been similar issues. I have not heard of this issue on taurus platform vehicles, but it can still be given the same attention. Older vehicles had sticky starter relays you could tap on when it was cold and damp if yours does not actually have a mechanical cause at the switch.