Fan stopped working

I have a 2001 Ford Focus. A year or two ago, I noticed that the fan (and therefore front defroster) really only worked when it was on the maximum setting. I was and still am a poor student, so I didn’t bother to get it fixed. A few days ago, I noticed that the fan was no longer working at all, even if it was on the maximum setting. I checked the fuse under the hood and it was in fact blown. I bought a new fuse and replaced the old one, thinking that I would lick the problem. Unfortunately, no such luck. Based on my reading, it sounds like the blower motor needs to be replaced, but I don’t want to sink tons of money in a project if that ain’t it. Does my suspicion sound reasonable or is there something else I should check?

Now, if that sounds right, I figure this is something that I can do by myself fairly easily. Will I need to purchase a new wheel as well, or just a new blower motor?

It does sound like a blower motor has been failing. Whether you need a new blower wheel depends upon whether the existing one is damaged or gets damaged during removal for transfer to the new blower motor.

If this wheel uses a nut to attach it to the motor with I would suggest a drop of Loc-Tite on the threads to secure the nut. Odds are it won’t come loose without the Loc-Tite but I always prefer safe over sorry.

Sometimes a faulty blower motor can burn the resistor out. This could be verified by checking for power at the blower as the switch is turned through the various speed settings.
You could also plug the new motor in sans wheel and with good fuses and test motor operation that way if you don’t have a test light or VOM. Hope that helps.

(Doing that test sans the wheel is to assure the motor doesn’t leap off the carpet when it’s turned on and shatter the wheel or maybe chew up a fingertip…)

If I need to replace the resistor, will I need to replace the cable as well? Also, could you provide a bit more detail about checking the power with a multimeter or test light? Thanks.

You should not need to replace anything other than the blower and resistor if needed. In some cases it’s possible that a blower motor connector will need to be replaced due to it burning from years of high current draw. Current is the amount of electricity being consumed and also means heat. This is a visual inspection when the blower connector is unplugged. This is not a major fix if needed.

The wiring schematic shows a green/orange lead which should have 12 volts provided all the time from a 30 amp fuse.
The voltage passes through the motor and then through a black/red lead which then morphs into a black/blue to the resistor and a black/orange to the fan switch.
Voltage drops are though the resistor.

Rather than overload you with more detail on the resistor wiring I would suggest that you remove the blower and determine if it’s seized up. A pair of jumper wires (hot and ground) could be run to the blower motor connector as a test but if the blower is seized that could mean a bit of an electrical arc, some hot wiring in hand, and potential for a burn.
Maybe this will be a decent starting point anyway. If additional help is needed post back and I’m sure you will receive more assistance from me or one of the many other knowledgeable posters here.

One way to check for a bad blower motor is, turn the ignition switch on. Set the blower speed to high. Reach under the passenger side of the dash, and with the handle of a screwdriver rap on the blower motor.

If the blower starts working replace the blower motor.