* Blower Motor Resistor: This is a common culprit. It controls the fan speeds. A faulty resistor can cause the fan to not work at all, or only work at one speed (often high). This is a relatively inexpensive and easy part to replace.
* Blower Motor Relay: This electrical component activates the blower motor. A bad relay will prevent the motor from receiving power.
* Fuse: Check the fuse associated with the blower motor. A blown fuse is a simple fix.
* Wiring: Check all wiring to the blower motor, resistor, and relay for any breaks, loose connections, or corrosion. This includes the switch itself.
* Blower Motor itself: Only after checking all of the above should you suspect the blower motor itself. Sometimes they can fail, but it's less common than the other problems listed.
Recommendation: Start with the easiest and cheapest options first: check the fuse and inspect the wiring. Then, move on to the blower motor resistor and relay. A qualified mechanic or automotive electrician can diagnose the problem quickly and accurately if you're not comfortable doing this yourself. Replacing the motor prematurely will cost more than addressing the simpler potential issues.
