BMW 3 of the E46 series

since 1998 release

Repair and operation of the car


BMW 3 of the E46 series
+ BMW 3 Cars (E46)
+ Current leaving and service
+ Engine
- Cooling systems, heating
   - Engine cooling system
      Replacement of cooling liquid
      Check of a thermoswitch
      Check of the cooling system under pressure
      Connection and separation of the quick disconnect coupling
      Removal and installation of the thermostat
      Removal and installation of a fan / casing of the fan
      Removal and installation of the fan with the viscous coupling
      Removal and installation of a radiator
      Removal and installation of the pump of cooling liquid
   + Heater and conditioner of air of salon
+ Power supply systems, injection and release
+ Electric equipment of the engine
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment


Check of a thermoswitch

The thermoswitch is at the lower shlan on a radiator. It connects the electric fan when temperature of cooling liquid reaches a certain value.

Check conditions:

- The thermoswitch needs to be checked if at a hot radiator the electric fan does not work.
- If the lower hose of a radiator warm, the thermostat is serviceable. With malfunction of the thermostat the thermoswitch cannot connect the fan as it does not get warm cooling liquid.

Check of a thermoswitch without removal

1 Rasstykuyte thermoswitch socket.
2 Connect both contacts on the plug an auxiliary cable. If now the fan starts working, malfunction is in a thermoswitch. Replace it. Fix a new thermoswitch with a new sealing ring the moment of 20 N • m.
3 If despite a thermoswitch crossing point, the switch does not work, check reliability of connection of the plug with the electric motor of the fan and reliability of contact. Check electric wires, the relay and electric motor of the fan. Check electric elements, address to the Head Onboard electric equipment.

Check of the removed thermoswitch

4 The thermoswitch can be checked also after removal. For this purpose it is necessary to attach an ohmmeter to contacts of the switch.


5 Ship a thermoswitch in hot water to the level of a carving and measure resistance. At a temperature of +93 ± 2 °C resistance has to make 0 Ohms, at a temperature below +89 °C resistance has to be infinite.