Thermostat, or fan motor if it does not blow hard.
Try Blower Motor Resistor. It would on the Passenger side under the dash
electric fans are run by a sensor that turns it on when the engine has reached a certain temp. if the engine isn't hot enough or isn't workin hard enough the fan wont kick on
You may have a faulty switch that controls the speeds on the a/c blower fan.
i hsd the same problem with my 1990 520i. replace the fan clutch. your fan is not spinning fast enough. if that doesnt work replace the radiator.
it should blow directly to the condenser
she doesnt have a fan club, she would have to get fans first.
If a fan is operated in a vacuum, it will not blow while turning.
Check the fuses, check the relay and then check the fan motor.
Bad blower motor? Blown blower motor fuse? Bad fan switch? Bad blower resistor pack?
Fuse blown
probably the fan relay