10:19. Wires and safety locks

In the Mercedes cars separate wires are, as a rule, collected in plaits and put into a black braid that complicates search of a necessary wire. To help orient numerous shtekerny sockets which exact position and number of the entering wires is specified in schemes of electric equipment can in this case. Section of a wire is selected depending on the consumer's power: for a control lamp there is enough cross-sectional area of 0,5 mm2, the wire of 16 mm2 is necessary for a starter. Too thin wire can overheat therefore tension falls. As a result headlights are reached, for example, not by(with) 12 V, but 10 or even 9,5 B — their light dim.

Fig. 9.36. Arrangement of the assembly block: 1 – ABS/ETS controller; 2 – EDS controller; 3 – contact sockets for various electronic devices (depending on a complete set); 4 – dual valves of system of heating


Two wires are connected to most of consumers. But usually it is possible to track a way to the battery or the generator only for one of them. Other wire often already in several centimeters is attached to metal details of a body, the engine or transmission. It is a bright example of how auto makers used for the purposes the physical principle according to which the metal details called by auto electricians "weight" carry current. Thus, a large number of wires on short circuit of a chain from the consumer to the negative plug of the battery is saved, transferring this function to "weight". If any consumer does not work, often the lost contact with "weight" is the reason. In this case the contact with "mass" of this consumer is made in roundabout ways that causes violations in the general system. For work with electric equipment a certain endurance is necessary. The tables of safety locks and electrical circuitries presented in this book will help you with everything to understand. The assembly block (fig. 9.36) is located under the cover protecting from moisture and splashes in a back right part of a motor compartment.
   The negative wire of the rechargeable battery connects to "weight"
The current supply to the consumer is carried out on a wire which way with big or smaller difficulties can be tracked to the rechargeable battery that is also reflected in electrical circuitries. The return chain is provided by the metal details of a body or the engine installing electrical equipment. A large number of wires is so saved. In certain cases the return chain nevertheless requires a short wire — usually when the consumer settles down directly on metal details. These, always conduct so-called wires of "weight" to the points or contacts of "weight" distributed on a body and which the ends of wires join on threaded connections.
The negative plug of the rechargeable battery is connected to a body or with "weight" as auto electricians call. Always you remember it: "minus" connects to "weight".