1. The Obvious Checks (Do these FIRST):
* Bulbs: This is the most common cause. Check both brake light bulbs in the taillights. They often burn out together. Replace them with the correct wattage bulbs (check your owner's manual or the bulb itself for the correct rating). While you're at it, check the turn signal and running lights bulbs as well, just in case.
* Fuses: Check the fuse box (usually under the hood or in the dashboard) for blown fuses related to the brake lights. Your owner's manual will show you a fuse diagram. Look for fuses labeled "brake," "taillights," or something similar. Even if one brake light works, a blown fuse could be affecting both.
2. Beyond the Basics (If the above didn't fix it):
* Brake Light Switch: This switch is usually located near the brake pedal. It's a small switch that activates when you press the brake pedal, completing the circuit to the brake lights. It can wear out or get stuck. You can:
* Inspect it: See if it's visibly damaged.
* Test it: You might need a multimeter (a simple one is inexpensive) to test if the switch is closing the circuit when the brake pedal is pressed. (Many online tutorials show you how to do this)
* Replace it: If faulty, this is a relatively inexpensive and easy part to replace.
* Wiring: Worn or corroded wiring can interrupt the circuit. Inspect the wiring harness leading from the brake light switch to the taillights. Look for broken wires, loose connections, or corrosion. Pay close attention to the connectors.
* Tail Light Assemblies: The problem could be within the taillight assemblies themselves. Check for corrosion or loose connections inside the taillight housing.
* Ground: A poor ground connection can prevent the lights from working. Locate the ground wires for the taillights and make sure they are clean and securely connected.
* Central Tail Light System (if applicable): Some vehicles had a central tail light system, which could be faulty.
3. Troubleshooting Steps (Using a Multimeter):
A multimeter is very helpful here. If you're comfortable using one, you can test:
* Voltage at the Brake Light Bulbs: With the brake pedal pressed, check for voltage at the brake light bulb sockets. If there's no voltage, the problem is before the bulbs.
* Voltage at the Brake Light Switch: Test for voltage at the switch terminals, both with the brake pedal pressed and released.
* Continuity of the Wiring: Test the wiring between the brake light switch and the taillights for continuity (to ensure there are no breaks in the wire).
4. Seek Professional Help:
If you've checked all the above and the brake lights still don't work, it's time to take your Explorer to a mechanic. There might be a more complex electrical issue requiring specialized tools and knowledge.
Safety Note: Driving with non-functioning brake lights is extremely dangerous. Do not drive your Explorer until the brake lights are working correctly. You can use temporary warning measures like a flashing triangle or a brake light bulb that is stuck on to increase your visibility and safety.
