Abstract: A controlling system is provided for use with a motor vehicle which includes auxiliary equipment usually being pneumatically powered and designed to be operated by a power take-off switch wherein throttle control by the accelerator pedal of the motor vehicle is blocked during operation of the power take-off equipment and wherein control of vehicle motor operating speed is controllable through a throttle control system accessible within the vehicle driving compartment or externally. The apparatus is preferably all pneumatically controlled and is connected to receive pressurized air from the vehicle air tank which itself is also used to operate other equipment such as air brakes and the power take-off equipment itself.