Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car



Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
- Cooling system
   Check of level of cooling liquid
   Frost resistance check
   Check of the cooling system on tightness
   Radiator
   Carving cover of a broad tank
   Thermostat
   List of malfunctions
   Water pump
   Maple belt of the water pump
   Cooling system fan
   Malfunctions of the fan of the cooling system
   List of malfunctions
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signaling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications





Cooling system fan

Audi 80 is supplied with the fan with the electric drive which is connected only if necessary. Thereby fuel is saved.

Therefore in a radiator the thermosensitive switch is screwed in. If he "feels" that the liquid proceeding by it after passing of a radiator still heating, it turns on the fan by means of the relay on a shtekerny cell 2. In the same way it switches-off the electric fan if temperature in the lower part of a radiator fell up to the certain size.

Two-level fan of the cooling system

In some Audi 80 options it is supplied with the two-level fan. At big load of the engine and according to more high temperature of cooling liquid the thermoswitch includes higher speed of the fan. It is possible thanks to a two-level thermoswitch which includes the second way of current to the fan via one more relay located in a shtekerny cell 11.

  • In certain versions of equipment Audi 80, for example, with the 4-cylinder engine installed at the plant by the traction and hook-on device (turnbuckle) or on cars with the strengthened cooling system – the additional fan near already mentioned cooling system fan is installed. It is given by means of a maple belt of the first fan.
  • On models with the 5-cylinder engine there is no place for the second fan of the cooling system. Therefore at installation of the traction and hook-on device at the plant this engine is equipped with more powerful engine of the fan.
  • Models with the 6-cylinder engine in a basic equipment are supplied by one, in special execution – two fans given separately.

On an illustration fans of the cooling system of the 4-cylinder engine with the strengthened cooling system are shown. It functions as follows: actually the fan of the cooling system (2) gives the second fan of the cooling system (1) by means of a small maple belt.

At the 6-cylinder engine of a similar design the two-level fan stands still. Cars with the strengthened cooling system are supplied – opposite – two two-level fans, everyone with own drive.

The thermoswitch of the fan of the cooling system is established on a radiator below. Illustrations show: at the left – the 4-cylinder engine, on the right – 6-cylinder. Except shown, there are options of osnashcheniye at which the thermoswitch is installed on the left side of a radiator.

Temperatures of switching of a thermoswitch of the fan

 Version of the fan
Inclusion temperature
Switching off temperature
One-stage
92 – 97 °C
84 – 91 °C
Two-level
  • first step
92 – 97 °C
84 – 91 °C
  • second step
99 – 105 °C
91 – 98 °C

Electric switching

Electric circuits of connections you will find Electric circuits in the section. Separately in serial versions business looks as follows:

 PERFORMANCE ORDER

  1. 66 kW 4-cylinder engine: the thermoswitch operates the fan not directly, and via the relay on a shtekerny cell 2 central switchboards. That is it is in a chain of management of the relay and defines when contacts which switch a current from the plug 30 (which is constantly energized) to the fan have to be closed.
    The chain of management receives current from the plug X only at the included ignition so contacts of the relay can be closed only in the provision of the included ignition.
  2. 85 kW 4-cylinder engine and 5-cylinder engine: on these models the two-level fan with a certain double switching is installed: the double thermoswitch operates via the relay on a shtekerny cell the 11th slower step of operation of the motor of the fan.
    At these engines switching is supplemented with so-called turning on of the fan after termination of work of the engine. It functions as follows: if in a motor compartment after a stop of the engine hot air stands, then the fan of the cooling system provides access of cold air. Thereby formation of steam traffic jams in fuel-supply lines of high pressure – the reason of problems of start of the hot engine is prevented.
    In this electrical circuitry the thermoswitch on a head of the block of cylinders "feels" temperature and turns on the fan via the control unit of turning on of the fan of the cooling system after termination of work of the engine on a shtekerny cell of the relay 3.
  3. 6-cylinder engine: here we deal with one or two two-level fans. The double thermoswitch (originally its part for the first step) passes via the relay on a shtekerny cell the 11th current for the first speed of the fan. The slowed-down rotation is reached by means of installation of the additional resistor which limits giving of food to the fan engine.
  4. If the thermoswitch connects the second speed of the fan, then giving of food goes via the relay on a shtekerny cell 18, – this time directly to the separate fan or to two engines of the fan bypassing a resistor plate.

 Hint: from electric connection via the plug X (see also head the Body electrical system) it turns out that the cooling system fan – is unimportant, one - or two-level – at the switched-off ignition cannot begin work.

Otherwise the situation is at models with the 85 kW 4-cylinder engine and with the 5-cylinder engine because of function of turning on of the fan of the cooling system after termination of work of the engine. Here the fan can start working also at the switched-off engine. Therefore be careful during the works in a motor compartment!








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