Heater defroster fan will not work in 2003 Ford

Usually bad blower motor resister mounts into the heater box under hood.

Check fuse, if fuse ok, is there electric current to blower motor ? If yes current to motor ok and still no air flow in vents , fan motor replacement !

the fan motor is maybe bad, disconnect it (the motor) and put in new fuse, if its ok, then the motor is bad. the resistor only handles speeds lower than HIGH. so replace the motor first, then try it, if all speeds work, then the resistor is OK.

Cars usually overheat when the thermostat is faulty, coolant level is low, or the water pump fails. If your cooling fan on the radiator does not kick on shortly after the engine reaches operating temperature, you may have a bad cooling fan, cooling fan relay, or cooling fan fuse. If your engine is overheating, start by checking the fluid level, and installing a new thermostat.

A blower motor resistor is the device that controls a car's cabin heating and air conditioning unit's fan speeds. This usually won't cause the engine to overheat, your A/C fan may not function or only function at one speed. Here is a Blower Motor Resistor from Autozone: http://www.autozone.com/autozone/parts/2003-Ford-Focus/A-C-Heater-Blower-Motor-Resistor/_/N-jk8uvZ91tag

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check the blower motor fuse, then you can turn truck on put the speed control to high. if fuse is blown replace fuse, if the speed control only works on high, the blower motor resistor needs replacing. It is on passenger side under glove box in close proximity to the blower motor. The fuse is under the hood on driver side. the cover should say fuses/relay on the top of cover, on most ford vehicles you will need to look in the owners manual for the position of the fuse.

check blower moter relay or fuse ..if ok probly the control switch fan blower control switch....

Check fuse panel for blown fuse first.

Your blower motor resistor has gone bad, it should be located next to your blower motor in the car, held in place with a couple of screws, remove it and replace it. The resistor is responsible for making the blower motor run at slower speeds than high or (4). Let me know if this helps.

no heat or no blower. HUGE difference between those two symptoms. Clarify

The blower motor resister is bad...It is very common in chevy trucks. The resister is located behind the glove box and is held in place by two screws, it will also have a wire harness attached to it. If you want to see a picture of it go to www.partsamerica.com and search for the blower motor resister.