The electro-hydraulic power unit, also known as the hydraulic unit, is the beating heart of the tail lift. It is this unit that pressurizes the oil used in the equipment. A power relay allows the start of an electric motor that acts on a pump which generates pressure by drawing oil from a tank. Through a logic unit or hydraulic block, the correct operation of the hydraulic power unit and the sorting of oil in the various pipes of the system are guaranteed. The control units are generally of several structural types. Some of these are mounted internally in the main bank frame and therefore remain fully protected, closed and preserved from the latter. Normally it is accessed by opening a tubular cover and removing the control unit from the inside. A second type of control unit involves the use of an external box, fixed to the vehicle, consisting of a box or support and a cover. This is generally held by hooks or tie-rods that allow access quickly and easily. The complete control units, obviously having electrical components, can be supplied with both 12 and 24 Volts.