On some side of the water radiator, you will find a thermocontact that is threaded to it and that wears three cables in a connection tab. Disconnect it and if the fan for that is your problem. Replace this element with another, then you will have to fill in the antifreeze radiator and ask, if you do not know where the air purges of the cooling system are.
Note: The radiator thermocontact has nothing to do with the tarmoresisision that you have changed, which serves as an indicator of the temperature in the interior clock in the instrument frame and which is usually placed in the thermostatic valve of engine coolant output or in its vicinity.
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