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
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
The ignition switch is bad. Replace it.
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.
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...
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
There may be a fuse blown if the power vent windows don't work on a 1999 Dodge Caravan. If the problem isn't the fuse, the motor in the power windows may need to be replaced.
check fuses,see if ones blown check power at blower, don't forget the fan switch ,there famous for going out.
Check the fuse and blower relay first. Make sure that there is power getting to the blower motor before changing the motor.
The Heater Blower Relay on a 1993 Ford Explorer is located in the Power Distribution Box. The PDB is in the engine compartment, mounted on a bracket attached to the right fender apron. The Heater Blower Relay is one of six relays, the first relay on the upper left.
Defective heater resistor pack.
First guess would be a bad ignition switch.
check the hvac fuse first if that is ok check the thermistatic control switch make sure you have power going to the blower motor if there is power the blower motor is bad
Check to see if you are getting power to blower motor--if so, bad blower motor If no power- perhaps bad resistor pack at blower motor Bad switch?
The most likely cause is the blower motor, if you unplug it and the fuse doesn''t blow you will have an answer.
That's too bad
( # 19 ) in the Power Distribution Box ( which is " live " ) located in the engine compartment is a ( 40 AMP FUSE FOR THE HEATER BLOWER MOTOR ) on a 2007 Ford Focus
The heater blower motor is #19 in the power distribution box under the hood, which also houses your relays.
I had the same problem. I had to smack the steering wheel to get the airbag light to go out. Then the heater and windows would work. Eventually, the car would start with my foot on the brake, but would stop when I took my foot off. When I had the ignition switch replaced, everything worked again.