I've heard through friends that when that happens its the blower resistor (about $20).I've removed mine but mine was good,so I put it back. It will be below the dash on the passenger side. If you get under the dash and look up, you'll see a connector hooked to something going into a duct between the motor and dash. Disconnect that by sliding the red lock tab to the right (while looking up) and pull apart. There are two 5/16" screws holding it on and that will be the resistor. You can also get to it by removing the glove box but its tight. Good Luck!