Audi A4

Since 1994 of release

Repair and car operation



Audi А4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ Exhaust system
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and channels всасывания
+ Injection system
+ Coupling
+ Transmission and the main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tyres
- The electrotechnical equipment
   The minus is connected to weight
   The help for orientation in the electrotechnical equipment of the car
   Wires
   Connections of wires
   The central switching knot
   Support of additional relays
   Box for electronics
   The relay and management blocks
   The switching relay
   H-contact of the relay of unloading
   The table of the relay and management blocks
   Safety locks
   The table of safety locks
   + Electric schemes
   + The accumulator
   + The generator
   + Starter
+ Ignition system
+ Illumination
+ The alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics










The relay and management blocks

A number of the relay and blocks of management which are placed in a protective box at the left under a control panel or under facing of a steering column concerns the onboard electrotechnical equipment.

  • The simple switching relay is used for powerful consumers of a current. If the current arrives long bypass ways on wires through corresponding switches there is a pressure loss. Besides, contacts of switches are exposed to strong loading at the expense of a current of the big force. At relay switching switches are used only for a weak switching current thanks to what the consumer is connected not directly, and through the relay.
  • If the signal about switching goes not from the switch, and from the electronic block of management, the same law operates: sensitive electronic knots cannot spend currents of the big force without damages.
  • Certain relays can carry out additional functions. For example, the relay-breaker of faltering impulses, the relay of switching of intervals in work of system of washing/clarification of glasses operates an interval in work and movement of screen wipers dry after washing of glasses.
  • Management blocks possess more or less extensive electronic schemes of switching of certain functions, sometimes establish also one more relay. As an example it is necessary to name the management block the central lock and systems of the prevention of breaking.