1. Check the Brake Light Switch:
* Location: This switch is usually located near the brake pedal. It's a small switch that activates when you press the brake pedal.
* Inspection: It might be physically broken or worn out. You might be able to see if the switch plunger is moving when you press the brake pedal. A visual inspection might reveal cracks or damage. Often, they just wear out over time.
* Testing (Advanced): You can test the switch with a multimeter to see if it's closing the circuit when the brake pedal is depressed. (Consult a wiring diagram for your specific vehicle to find the correct terminals to test.)
2. Check the Bulbs:
* Obvious but Important: While you mentioned the tail lights work, ensure the brake light bulbs themselves aren't burned out. Brake lights often share a dual-filament bulb with the tail lights; the brake light filament might be blown while the tail light filament is still intact.
3. Check the Fuses:
* Location: Consult your owner's manual for the fuse box location and diagram. There should be a fuse specifically for the brake lights.
* Inspection: Carefully check for blown fuses. They'll usually have a broken filament visible inside.
4. Check the Wiring:
* Difficult but Necessary: This is the most challenging aspect. There could be a break or short in the wiring between the brake light switch and the brake lights themselves. You'll need to trace the wiring harness looking for any damaged or corroded wires. This often involves carefully inspecting connections and looking for any obvious breaks in the insulation.
5. Check the Brake Light Circuit (Advanced):
* Multimeter Required: Using a multimeter, you can test the voltage at the brake lights themselves when the brake pedal is pressed. If there's no voltage, the problem is likely in the wiring or the brake light switch.
Important Considerations:
* Wiring Diagram: A wiring diagram specific to your 1993 Ford Explorer is highly recommended. This will help you identify the correct fuses, wires, and components involved in the brake light circuit. You can often find these online through automotive repair websites or forums.
* Safety: Driving with non-functional brake lights is extremely dangerous. Do not drive the vehicle until the problem is resolved.
If you're not comfortable working with car electrical systems, take your Explorer to a qualified mechanic. Brake lights are a critical safety feature.
