G'day Norwegian .
You can have the cold weather!!.
When using the diff lock you have to keep your foot on the pedal all the time it is in use, as soon as you take your foot of the pedal and the torque load is lost the pedal will spring up /out of engagement this is how it works,not like a truck where it is held engaged with air or whatever.
Hutch.
Aha. Thanks for that, should be all good then