Cooling system malfunctions (General information / Help with malfunctions / Ford Mondeo 3 2000-2007)

Cause	elimination
A. The temperature warning light comes on
V-belt loose or broken Not enough liquid in the cooling system The connecting wire to the signal lamp has a ground connection. Thermostat stays closed (radiator cold). The cooling fan is not working. The pressure reducing valve in the sealing cap of the expansion tank is defective. Connection to the mass of the temperature indicator sensor. The radiator is dirty or the fins are damaged.	Check the belt tension or replace it. Top up with water, in extreme cases, take it from the windshield washer system. Disconnect the temperature sensor wire, the signal light should go out. If not, then there is a ground connection; check wire routing. Stop, dismantle the thermostat, continuously check the temperature. Have the vehicle towed to a workshop if necessary. Defective fan motor, replace. Defect in the temperature sensor. Disconnect the conductive wire from the sensor and directly connect to the terminal of the wire coming from the sensor. Check the valve, check the bonnet seal, if necessary replace the locking bonnet. Replace. Thoroughly clean the radiator. Entrust this matter better to your workshop or specialist.
B. The engine slowly reaches the required temperature. Insufficient heating power.
The thermostat does not close completely, as a result of which a large circulation circle is constantly in operation.	Clean thermostat, replace if necessary.

Cooling system malfunctions