1. The Obvious Checks:
* Fan Speed: Is the fan completely off at all speeds? If the fan works on any speed, the problem is likely *after* the blower motor. If it's completely dead, the problem is *before* or *at* the blower motor.
* Blower Motor Resistor: This is a common failure point. It controls fan speeds. A faulty resistor often results in only high speed working (if anything), or no fan at all. It's usually located behind the glove box.
* Fuse/Relay: Check the fuses and relays related to the blower motor. Your owner's manual will show you their locations and what they control. A blown fuse is an easy fix.
* Blend Door Actuator: This controls the direction of the air (face, defrost, floor). If it's broken, you might not get air directed anywhere. These can be noisy or just not work.
2. More Advanced Troubleshooting (Requires Some Mechanical Skill):
* Blower Motor: A faulty blower motor itself is a possibility. This requires accessing the blower motor (usually under the dash) to test it directly with a multimeter.
* Vacuum Lines: Many older vehicles use vacuum lines to control the blend doors. A leak or blockage in these lines can prevent proper airflow. Inspect these carefully.
* HVAC Control Module: This electronic control unit manages the entire system. A failing module can cause numerous problems, including no air at all. This is usually a more expensive repair.
* Leaking Evaporator Core (AC only): If your AC is not working but the heat is, there might be a leak in the AC system's evaporator core, causing a loss of refrigerant. This requires AC system diagnostics and repair.
* Low Coolant (Heat only): If your heat is not working, check your coolant level. Low coolant can prevent heat from reaching the heater core.
3. Where to Start:
1. Check the fuses and relays first. This is the easiest and cheapest thing to check.
2. Test the blower motor resistor. This is a fairly common and relatively inexpensive part to replace.
3. Listen for any clicking or whirring sounds when you turn the fan on. This might point to a problem with the blower motor or blend door actuator.
4. If you're not comfortable working on your car's electrical system, take it to a qualified mechanic. Misdiagnosis can lead to unnecessary parts replacement.
Important Note: Always disconnect the negative battery terminal before working on any electrical components in your vehicle.
By systematically checking these points, you should be able to narrow down the cause of your Windstar's heating and AC problem. Remember to consult your owner's manual for specific fuse and component locations.
