Audi A4

since 1994 release

Manual of the car

Audi A4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
- Cooling system
   So there is a cooling
   Check of level of cooling liquid
   Antifreeze check
   Check of the cooling system on tightness
   Locking cover of the cooling system
   The help at malfunctions
   Water pump
   Maple belt of the water pump
   Various models of fans
   Viscous fan
   The radiator fan with the electric drive
   Violations in operation of the fan of a radiator
   The help at malfunctions
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
+ System of injection
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics


Violations in operation of the fan of a radiator

If the thermostat fails or it is torn maple the belt (only at the four-cylinder engine), can lead the idle fan of a radiator to too considerable increase of temperature of cooling liquid.

After the engine a little cools down, it is possible to reach to the next workshop on average turns and at the smooth movement. At the same time do not lose sight of the indicator of temperature and an alarm bulb.

On the contrary, idling and the creeping speed are deadly to the engine. In these conditions through plates of a radiator there does not pass the cooling stream of fresh air. If continuation of a trip because of traffic conditions is possible only at a low speed, then you have to find out a cause of defect and in the presence of the fan with the electric drive at once if it is necessary, to put a crossing point on a thermoswitch.

Malfunctions in the viscous fan

Viscous coupling has to be replaced if:

  • at the idle engine the fan easily is not turned;
  • at the fan a big axial and radial beating (the small gap is admissible);
  • silicone oil acts from viscous coupling.

Violations in operation of the viscous fan


  1. In the beginning check additional safety locks (see the head the Electrotechnical equipment).
  2. If they as it should be, then switch-off the thermoswitch socket.
  3. Peremknite both contacts in the wire socket a piece of a wire.
  4. Peremknite all three sockets in a two-level thermoswitch.
  5. If now the fan at the included ignition works, then (in this case empirically) the thermoswitch brought out of an electric chain – often found malfunction is faulty.
  6. To continue a trip, clamp a wire crossing point in the socket and reliably insulate an adhesive tape or a plaster in order to avoid short circuit.
  7. If the peremykaniye of a thermoswitch did not help, check the fan relay in the central switching knot (see the head the Electrotechnical equipment). If both wires of a thermoswitch of a peremknuta, then have to be heard as at inclusion of ignition contacts of switching in the relay become isolated.
  8. If it not so, then becomes a temporary crossing point in the relay. For this purpose connect a piece of a wire contacts of the socket of the relay of plugs 30 and 87 (an office paper clip) and insert the relay.
  9. The fan of a radiator has to work even at the switched-off ignition. If this is so, then is faulty the relay.
  10. The crossing point from a wire can be used as the temporary help on the way. After a trip it needs to be removed.
  11. If not to achieve success in such way, then check the fan engine:
  12. Disconnect the wire socket to the engine of the fan and instead of it connect to contact of a red/black wire an auxiliary wire to the positive plug of the accumulator. Connection of the socket of a brown wire is connected directly to the negative plug.
  13. If the propeller still does not rotate, then the fan engine is faulty – replace it.
  14. But if the fan works, then relays (see the head the Electrotechnical equipment), sockets of wires, and also all connections of a thermoswitch and the electric fan have to be checked.
  15. You without cares can continue a trip also with the radiator fan receiving a power supply directly from the accumulator. The auxiliary wire has to be isolated in order to avoid short circuit.