I have a 2002 mini cooper r53 and my radiator fan does not work, i found some information about it in this forum so i check that the fan is working properly by putting 12V on the "auxiliar" cables and it seems that the low and hight speed works just fine but, when the temperature in the car increases the fan does not turn on, the coolant boils and spills from the expansion tank. Can anyone tell me what i should test now? im a litle lost but i want to learn about what is possibly going wrong with this

 

I’m replying to myself because I finally found what’s wrong, minis between 2000-2003 have a 5a fuse that control the on and off of the cooling fan for refrigeration, that’s why a/c works, because it has another fuse for that, the fuse for the cooling fan is in the 5 position in the fuse box under the hood