* Blower Motor Resistor: This is a common culprit. It controls the different fan speeds. If it fails, you might have no fan at all, or only the highest speed might work (if at all). It's often located behind the blower motor itself, sometimes within the HVAC housing. This is usually a relatively inexpensive and easy repair.
* Blower Motor: The motor itself could be faulty. This is less likely if you're getting power to the relay, but a shorted motor could still prevent it from running. Testing the motor directly (with caution!) with a multimeter would help diagnose this. This is more expensive to replace than the resistor.
* Wiring: There could be a break or short in the wiring between the switch, the resistor, and/or the motor. This is harder to diagnose and requires tracing the wiring. Look for any obvious damage to the wiring harness.
* Switch: While you suspect the switch is working since you have power to the relay, it's possible the switch is faulty, even if it *appears* to be working. It might be internally broken, providing power to the relay only intermittently or under specific conditions, or sending the wrong signal.
* Bad Ground: A poor ground connection anywhere in the circuit can prevent the blower from working. Check the ground connection for the blower motor and the HVAC system itself.
Troubleshooting Steps:
1. Check the Blower Motor Resistor: This is the easiest and cheapest thing to check first. Locate it (consult a wiring diagram for your specific Escort model if needed) and inspect it visually for any obvious damage. You can also test it with a multimeter for continuity, but this requires some electrical knowledge. Replacing it is often a simple matter of unplugging and plugging in the new one.
2. Test the Blower Motor (with caution!): Disconnect the wiring harness from the blower motor. Using a multimeter, check for continuity and resistance within the motor itself. Be extremely careful doing this as the motor is electrically charged even when the car is off. Incorrect use of a multimeter could result in injury. If you're not comfortable with this, skip this step.
3. Inspect Wiring: Carefully inspect the wiring harness from the switch, to the resistor, to the blower motor for any breaks, shorts, or corrosion. A visual inspection might show frayed wires or damaged connectors.
4. Check Ground Connections: Locate the ground connections for the blower motor and the entire HVAC system. Clean them thoroughly with a wire brush and ensure a good, solid connection.
5. Test the Switch (most difficult): This is the most involved test, requiring you to backprobe the switch wires with a multimeter to ensure it's sending the correct signal when activated.
If you're not comfortable working with car electronics, it's best to take your Escort to a qualified mechanic. They will have the tools and expertise to properly diagnose and repair the problem efficiently. A wiring diagram specific to your 1997 Ford Escort will be incredibly helpful in any of the troubleshooting steps. You can usually find these online through various repair manuals or forums dedicated to Ford Escorts.
