BMW Questions? Ask a BMW Repair Expert for Answers.
The most common problem with your symptoms is a faulty blower motor resistor,( "blower motor final stage", is the BMW term.) We see these fail a lot but keep in mind an intermittent shorted wire is always a possiblity. If it stops working again i would replace the blower resistor while its not working and retest. If it begins to work again you've found your problem.
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