There are some fusible links located under the hood near the engine control module on the center of the firewall. Check both sides of them with a test light (with the key on) and you will probably find one that's bad. Replace it with a new one and you should be fine. Hope that helped! Mark
Start out by checking that the blower has both power and ground and if so then next check the a/c - heater controller...........
Work you way from the blower motor first by checking that it has both power and ground and then check the rest of the electrical system............
Check the fuse
fuse or relay most likely
The ignition switch is bad. Replace it.
Check to see if you are getting power and ground to the blower motor - if so blower motor is bad. If no power possibly fan switch or selector switch Also check the blower motor resistor, found in heater plenum.
blower motor bad or no power to it chech fuses blower switch blower motor
Year make model aside, most have power going to motor and grounds are through the blower motor resistor, setting speeds by using different resistors on the board, or in the case of automatic climate control, a power resistor control board, usually located in the heater box near the blower motor, google or ebay for one for your vehicle, get a picture of it in your head and look around the blower motor. They have diodes in them that fail and you will lose all speeds and other times, one or two.
Disconnect the battery. Remove the glove box to instrument panel screws. Disconnect the power and ground wires from the blower.. Remove the recirculating door actuator, the seven screws and then remove the complete recirculating housing.. Remove the three blower motor attaching screws.. Remove the blower motor...
You can test your heater blower motor by connecting a ground wire to the ground. Connect a power wire, from the battery to the positive post. If the blower motor turns it is working, and if it does not it is bad.
Blown Fuse, loose or disconnected wire, or defective blower motor resistor pack.
Check to see if you are getting power to the blower motor - if so motor is defective if not problem in circuitry to blower motor