you guys have to seriously pay attention to a cars workings before posting.
If your blower is only working on full speed and not lower - your selector resistor is dead, the full setting is operated by a relay. Buy a new resistor block and you'll be all set, you can also put it in yourself, its housed on the ducting of the blower motor output with a couple of screws - usually its a bunch of round wire coils but sometimes its also the shape of a credit card (nissan, new toyota etc)