To locate it more precisely:
* Look closely at the clutch pedal: Inspect the area where the pedal connects to the linkage. The switch is usually mounted directly to the pedal or very close to the linkage.
* Follow the clutch linkage: Trace the linkage back from the clutch pedal. The switch might be positioned along this linkage.
* Consult a wiring diagram: A wiring diagram specific to your 1989 F-150 will show the exact location and wiring of the clutch safety switch. You can often find these diagrams online or in a repair manual.
Keep in mind that the exact placement might vary slightly depending on the specific model and transmission type of your F-150. A repair manual for your truck's year, make and model will be the most definitive resource.