The following tells how to check the cooling fan system, both for basic operation and detailed troubleshooting, in case the operational check shows that one of the fan speeds isn't working.  If the operational check shows that both fan speeds are working, the best thing to do (and the one thing that fixes most people's cooling systems) is to buy and install the lower temperature fan switch.  Replacing the thermostat is also a good idea.  A lower temperature thermostat is available but I don't recommend it except in extremely hot environments because, coupled with the lower temp switch, the engine will actually run too cool.

In the US, the later 9000's all have the two stage cooling fan (not sure what year this started). It has been said that in cooler countries the fan is only single speed, but that one speed is the high speed.  The two speed fan system should have two relays (picture) and two fuses in the relay box at the left front of the car.  Also, the controlling temperature switch at the bottom right rear of the radiator should have three wires (single-speed fan temp switches have only two wires).  Photo of the switch location.

Actually, the two stage system is a single speed motor, but the low speed thermo switch closure goes to a resistor that is connected in series with the fan motor, where-as the high speed contact connects directly to the fan motor. The resistor for the lower speed is an obvious gold-colored object that is attached to the fan shroud.  Picture.  If you don't see it, then you probably have the single stage system (although on earlier versions the resistor was integrated into the fan and thus was not visible).

Simple operational check