AudiQua

I had to get under the car and disengage manually. I few questions:
1) The actuator under the seat doesn't work to disengage. When I applied vacuum manually it didn't disengage. I am guessing that the unit under the car is also shot. When the car exceeds the specified speed for the locked diff is it disengaged via the actuator under the seat?
2) I would like to temporarily deactivate the diff lock (I have a 2 year old that loves to push buttons). Can I jjust leave the blue and yellow vacuum tubes diconnected from the actuator under the seat and do I have to plug them up?

Thanks for the help.