My air conditioner is not working on my 2002 BMW X-5. The air is cool it just won't blow out.

If there is air moving through the vents most likely the final stage transistor(blower resistor) has failed. It controls blower speed from a signal from the ihka (a/c control panel). the final stage receives the signal from the ihka of the drivers preference blower speed. the final stage pwm (pulse width modulates) the blower motor. which means it turns it off and on very quickly to speed up or slow down the blower motor speed. It isn't the easiest part to replace. Usually at a dealership i would expect to pay somewhere around $600 (including diagnosis)but don't hold me to it. bmw dealerships stand behind their repairs and usually include a warranty with the part of 2 years unlimited mileage.