e46 318i - Testing engine cooling fan

[zulkifli]

Hi All,Does anyone know how to test the electric cooling fan on a 2000 e46. The unit is not relay controlled but has an electronic FCM (fan control unit), mounted on the fan frame, which has a permanent 12 volt supply and controls the fan speed using a PWM signal from the management control unit.Does anyone know how to test for presence of the PWM signal that the FCM should get to turn the fan on?Does anyone know if applying 12 volts to the terminals of the fan itself will damage the FCM (it may not like having 12 volts applied across its output terminals)Regard and thanks.