Checking the radiator fan thermal switch

The thermal switch must be checked if the fan does not switch on when the engine is hot. Prerequisite for the test: the coolant thermostat and the cooling system cap are in good condition.

The radiator fan thermoswitch is located on the left side of the radiator. Depending on equipment, either a 2-pin or a 3-pin thermoswitch may be fitted. The 3-pin thermoswitch is fitted to models with diesel engine or air conditioning. Note: the 1.8 L engine has no thermoswitch.

The radiator fan is switched on by the engine control unit.

• Check whether the radiator actually gets hot in the area of the thermoswitch.

• Check the fan motor fuse and replace if necessary, see page 248.

• Switch on the ignition.




• Disconnect the connector from the thermoswitch. Connect the terminals of the two wires to the thermoswitch with a short test lead. With a 2-stage fan, check both stages in this way. First connect the earth terminal to terminal 1, then to terminal 2.

• If the electric fan now starts, replace the thermoswitch.

  Tightening torque for thermoswitch: 25 N·m.

  Replace leaking coolant. Refill the cooling system, see page 71.

• If the fan does not start, check the electrical wiring according to the wiring diagram. Check connections for good contact and secure fit. Replace the fan motor if necessary.

• Check the function of the new thermoswitch. Run the engine warm and let it idle until the coolant fan switches on.