WWilder:
Are you sure the steering wheel locking mechanism is not simply jammed a little?
Gently work the steering wheel back and forth in both directions while trying to gently turn the key.
NCV3's have had some steering lock issues in the past.
As far as putting your gear selector into neutral, there is an interlock that you can trip that holds the gear selector lever in
Park (P) when the key is not inserted.
Check your Owner's manual for how to access and trip the gear selector lock.
Basically you need to remove the small round (approx. 1 1/4" dia.) plastic plug on the back of the gear
selector housing (just below and behind the gear selector) and push the interlock pin until the gear selector
lever will move back away from the dashboard to the neutral position.
No need to remove the drive shaft unless you are going to be towed a long distance at speeds above 35 mph.
Sounds like you may have some sort of SKEEM problem.
Have you seen the words "Start Error" in your dash board display.
Do you hear several little whirring sounds when you insert the key?
If not the voltage at the key switch may be so low the SKREEM cannot work.
Do your door locks work to remotely lock/unlock your Sprinter?
If not, you may have blown one of the main high capacity fuses the are on the
positive battery cable connection. If so, you will have no power to anything.
Here's what my Operator's Manual has to say about the key not turning:
Problem Possible causes/consequences and Solutions
The key cannot be turned in the ignition lock.
The vehicle voltage is too low.
X Switch off all non-essential consumers, e.g. the seat heating,
interior lighting, and try to turn the key again.
If this does not work:
X Check and, if necessary, replace the starter battery.
or
X Jump-start the vehicle.
or
X Consult a qualified specialist workshop.
The key cannot be turned in the ignition lock.
The steering lock has jammed mechanically.
X Remove the key and insert it again into the ignition lock. Turn
The key cannot be turned in the ignition lock.
The vehicle voltage is too low.
X Switch off all non-essential consumers, e.g. the seat heating,
interior lighting, and try to turn the key again.
If this does not work:
X Check and, if necessary, replace the starter battery.
or
X Jump-start the vehicle.
or
X Consult a qualified specialist workshop.
You said you jumpered the interior (Main Starting) battery (under the drivers side floor board) to the
to the jump start terminal under the hood, or to the front (Auxiliary) battery?
If you have more than the one battery (under the drivers floorboard), I would suggest you disconnect any auxiliary Battery for sure,
and buy a small charger (or better still an new battery) and charge up the battery under the drivers floorboard.
If you have more than one battery, there could very well be an isolator for that battery and if the isolator fails,
the bad battery (either one) could easily draw the current down to the levels you've measured.
Roger