if it works, take it
apart to finde out
AO Silver Member
Join Date: Dec 2008
I think Henrik 45 has a good point but also the temp sensor (depending on the model year of the car, either mounted on the radiator or on the thermostat housing) or any of the relays can be broken, so also check radiator cooling fan, there is a constant power on the fan (ignition on) so measure if you have 12V on one pin in the connector to the fan, if there is no power check fuse and if there is power earth the fan, if the fan does not start then is the fan probably broken and if the fan starts you may have problems with either the temperature sensor or the relays.
Aircon cycles radiator cooling fan depending on pressure in the aircon system, did you run aircon long enough to build up enough pressure to start the fan? but it has really no importance if there is no power to the fan.