The term has different meanings depending on context. In the aftermarket
engine business it is very common to sell "turn key" engine packages.
They are fully assembled, on a pallet, ready to ship and install, and
that is said right up front. Just google on the term "turnkey engine"
and see the many companies offering "turn key" that still have to be
installed. Like these below, from well known automotive suppliers.

http://cbperformance.com/turnkeys.asp

http://www.summitracing.com/parts/NAL-19210009

Mark

Dave Mcneely wrote:
> Good grief.  Where did the term "turn key" job come from?  From a job being complete to the point that the customer can simply turn the key and get on with life.  Applies to houses, vehicles, who knows what.  But it does apply to a situation as Ben described and as I just did.  There is no point in trying to make it less.  Anyone who does, is not adhering to the meaning.  mcneely
>
> ---- Rob<becida@COMCAST.NET>  wrote:
>> At  5/24/2012 06:13 PM, Ben T wrote:
>>
>>
>>> Once upon a time, a local shop did offer such services. I would
>>> drive/tow a Vanagon in with a Wasserboxer. A few days later, I would
>>> go over and settle my bill. Hop in the cab and drive away. Now
>>> that's "turn key". You turn the key in the ignition and go.
>>...............