So when i change the air speed on my RX it really doesn't change. It just slowly blows air. It sucks too because the AC doesn't blow fast enough for the car to cool down. Right now I'm getting ready to replace the heater core so I would also like to fix this problem too. Anyone have this problem?

 

Does it sound like the blower motor is increasing in speed/power when you go from 1-4 on the switch? You should be able to hear it "kick in" as you increase the rate. If not, you'll need to check your blower motor. If you hear it increase, then it may be that you have an obstruction in your hose, or a tear/break that is letting air leak.

If you are going into your heater core, you should be able to look into the above pretty easy.

 

Well when you turn it up it does increase but just a little bit. Going from 1 to 4 is like going from 1 to 2. When I'm going to take it apart and I'm going to see if it is blocked or something. I just want to make sure someone hasn't had this problem too. I hope I don't have to replace the blower motor.