Lift axle control

A wheeled motor vehicle comprising:

• an ignition switch for turning the motor of the vehicle on and off;
• an auxiliary lift axle that can be raised to lift wheels of the lift axle off an underlying surface on which the vehicle is supported and that can be lowered to place the wheels of the lift axle on the underlying surface;
• and
• a control for raising and lowering the lift axle comprising a circuit that is fed through the ignition switch when the ignition switch is on but not when the ignition switch is off and that comprises a first switch device that requires actuation to enable the lift axle to be lowered and a second switch device that, once the first switch device has been actuated to enable the lift axle to be lowered, is effective upon being actuated to cause the lift axle to be lowered.