1. Blower Motor Resistor: This is the most common cause. The resistor controls the different fan speeds. When it fails, you often get no fan at all, or only the highest speed (if at all). The clicking sound is the relay trying to engage the motor, but the resistor is preventing it from working correctly.
* How to check: Locate the blower motor resistor (often under the dashboard, sometimes behind the glove compartment). It's usually a small, rectangular black box with several wires connected. Visually inspect it for any obvious damage (burnt wires, melting, etc.). You can also try to ohm it out with a multimeter (if you have one), comparing the readings to a known good one or a schematic to see if it's within the expected resistance range.
* How to fix: Replace the blower motor resistor. It's a relatively inexpensive and easy part to replace, though accessing it can sometimes be tricky.
2. Blower Motor: The motor itself could be failing. While less common than a bad resistor, a seized or burnt-out motor will prevent the fan from working.
* How to check: This is more involved. You'll likely need to access the blower motor (often behind the dashboard) and check if it spins freely by hand. If it's seized or makes grinding noises, it needs replacement. You could also try testing it with a 12V power source directly (be cautious!), but this is only recommended if you're comfortable with electrical work.
* How to fix: Replace the blower motor. This is a more challenging repair requiring more disassembly.
3. Ignition Switch: Less likely, but a faulty ignition switch can sometimes affect the power supply to the heater blower. If other electrical components are malfunctioning, this could be a suspect.
* How to check: This requires a thorough electrical check by a mechanic. It's difficult to diagnose without specialized tools.
* How to fix: Replace the ignition switch – a more complex and expensive repair best left to a professional.
4. Wiring and Fuses: Check all fuses related to the heater and blower motor in the fuse box (usually under the hood or in the dashboard). Look for blown fuses (a broken filament inside the fuse). Also, visually inspect the wiring harness for any frayed, melted, or disconnected wires near the blower motor resistor and the blower motor itself.
Before you start:
* Disconnect the negative battery terminal before attempting any electrical work.
* Consult a repair manual: A repair manual specific to your 2001 Ford Windstar will greatly assist you in locating the components and understanding the wiring diagrams.
Recommendation:
Start with the easiest and most likely culprit: the blower motor resistor. If replacing it doesn't solve the problem, then move on to checking the blower motor, fuses, and wiring. If you're not comfortable working on car electrical systems, it's best to take it to a qualified mechanic.
