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
   Radiator
   Locking cover of the cooling system
   Thermostat
   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

The radiator fan with the electric drive

In Audi A4 the fan with the electric drive is put only in the presence of the strengthened cooling (the automatic transmission, the towing device in a factory complete set, climatic installation), it joins only in case of need.

Therefore the temperature and dependent switch is built in a radiator. If he "feels" that the cooling liquid proceeding by it after passing of a radiator still too hot, then turns on the fan by means of the relay in a nest 2 in "a vosmishtyrkovy support of the relay". It also switches off the fan electric drive when temperature below in a radiator falls up to the certain size.

The two-level fan of a radiator with the electric drive

In some Audi A4 versions there is a two-level fan of a radiator with the electric drive which thanks to existence of two steps of inclusion can react to temperature increase of cooling liquid more individually. It is possible thanks to a two-level thermoswitch which includes the second way of current to the fan via other relay in a nest 3 in "a vosmishtyrkovy support of the relay" and additional resistance.

Temperatures of switching of a thermoswitch of a radiator

Fan model	Inclusion temperature	Switching off temperature
One-stage	92–97 °C	About 84 °C
Two-level
1st step	92–97 °C	84 °C
2nd step	99–105 °C	91 °C

Council: Because of electric connection via the plug 30 the fan can suddenly turn on even at the idle engine. Be careful when carrying out to work in a motive compartment!

The thermoswitch (shooter) of the fan of a radiator with the electric drive in cars with the strengthened cooling is screwed below at the left on a radiator.