1. Diagnose the Problem:
* Fan doesn't run at all: This could be a blown fuse, a faulty relay, a bad temperature switch (often located in the radiator), a wiring problem, or a malfunctioning fan motor itself.
* Fan runs constantly: This usually points to a faulty temperature switch (it's stuck closed), or a short in the wiring.
* Fan runs intermittently or erratically: This suggests a problem with the fan motor, wiring, relay, or temperature switch.
Before you start, safety first: Disconnect the battery's negative terminal to prevent accidental short circuits.
2. Troubleshooting Steps:
* Check the fuse: Locate the fuse for the cooling fan in the fuse box (usually under the hood or inside the car, consult your owner's manual). Replace it if it's blown.
* Check the relay: The relay acts as a switch for the fan. Find the cooling fan relay (again, consult your owner's manual). You can often swap it with a relay of the same amperage from a non-critical circuit (like the wipers) to test it. If the fan works, you've found the culprit.
* Check the temperature switch: This is usually located in the radiator or on the engine block. Use a multimeter to test its continuity (resistance) at different temperatures. A faulty switch will either always show continuity (fan runs constantly) or never show continuity (fan never runs). You'll need the correct resistance specifications from a repair manual or online resource for your specific engine.
* Check the wiring: Visually inspect the wiring harness to the fan and the temperature switch for any damage, corrosion, or loose connections. Repair or replace as needed.
* Test the fan motor: With the fan disconnected from the vehicle, directly connect 12V power (with appropriate fuses and precautions) to the fan motor's terminals. If it runs, the motor is good; if not, it needs replacement. *Caution: Only attempt this step if you are comfortable working with 12V electricity.*
3. Repair/Replacement:
* Fuse: Replace with a fuse of the correct amperage.
* Relay: Replace with a new relay of the same type.
* Temperature switch: Replace with a new temperature switch.
* Wiring: Repair or replace damaged wiring. Use appropriately rated wire and connectors.
* Fan motor: Replace with a new fan motor. These are usually readily available for the '87 Ford Tempo.
4. Resources:
* Owner's Manual: Your best friend for fuse locations, relay locations, and other specifics.
* Repair Manual: A Haynes or Chilton manual for your specific year and model will provide detailed diagrams and instructions.
* Online Forums: Search for "Ford Tempo cooling fan repair" on forums like Ford-trucks.com or similar automotive communities. You'll find many others who have dealt with similar issues.
Important Considerations:
* Electric vs. Mechanical Fans: The '87 Ford Tempo may have either an electric or mechanical (clutch) cooling fan. The troubleshooting steps above primarily apply to electric fans. Mechanical fans require a different approach and often involve clutch replacement.
* Professional Help: If you're not comfortable working with automotive electrical systems, it's best to take your car to a qualified mechanic.
Remember to always consult your owner's manual and/or a repair manual for specific details about your vehicle. Improper repairs can lead to further damage or safety hazards.
