1. Fuses:
* Check the fuses: Your owner's manual will show you the fuse box location and which fuse(s) control the wipers. A blown fuse is the easiest fix. Replace any blown fuses with the correct amperage.
2. Wiper Switch:
* Test the switch: Try the different wiper speeds. If none work, the switch itself might be faulty. This can be tricky to test without a multimeter, but if other wiper functions (wash, intermittent) don't work either, it points strongly towards the switch.
3. Wiring:
* Check the wiring: Look for any broken, frayed, or corroded wires running to the motor from the switch and fuse box. Pay close attention to the connections at each end. A visual inspection might reveal a problem.
* Continuity Test (Advanced): Using a multimeter, check for continuity (a complete electrical circuit) between the wiper switch, the fuse, and the wiper motor. This requires some electrical knowledge. Lack of continuity indicates a break somewhere in the wiring.
4. Wiper Motor:
* Motor itself: If the fuses, switch, and wiring are all good, the wiper motor itself is likely the culprit. This is the most expensive part to replace.
* Testing the Motor (Advanced): You could try applying 12V directly to the motor terminals (with the correct polarity – a mistake can damage the motor). This is risky and should only be done if you're comfortable with working with electricity. If the motor runs when power is applied directly, the problem lies elsewhere in the circuit.
5. Ground Connection:
* Check the ground: A poor ground connection can prevent the motor from working. Trace the ground wire from the motor and ensure it's securely connected to a clean, grounded metal surface.
Troubleshooting Steps Summary:
1. Check the fuses. This is the easiest and quickest thing to do.
2. Inspect the wiper switch. Does it seem damaged or loose? Do other functions (wash, intermittent) work?
3. Visually inspect the wiring harness. Look for any obvious damage.
4. (Advanced) Use a multimeter to check for continuity.
5. (Advanced) Try applying 12V directly to the motor (use caution).
6. Check the ground connection.
If you're not comfortable working with electricity, it's best to take your F-150 to a qualified mechanic. Improper electrical work can lead to damage or even injury.
