why does my Ford F-150 13th Generation (2015-2020) headlights keep flickering

Ford F-150 13th Generation (2015-2020)

Error Codes

1-3 hours

Time

medium

Difficulty

medium

Severity

3 min read

562 words

Problem Statement

Learn how to diagnose and fix flickering headlights on a 2015-2020 Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Affected Component

Electrical

Estimated Time

1-3 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components.
•Allow the engine to cool before handling any components that may be hot.

Symptoms

•Headlight flickering or dimming while driving
•Potential dashboard warning lights illuminated (e.g., battery or electrical system warning)
•Increased frequency of flickering with engine RPM changes
•Headlights turning off briefly and then back on
•Possible malfunctioning of other electrical components (e.g., radio, interior lights)

Diagnostic Steps

1
Scan the vehicle's OBD-II system for any error codes related to electrical systems.
2
Inspect the headlight bulbs for signs of corrosion or damage.
3
Check the battery voltage and connections to ensure they are secure and clean.
4
Inspect the headlight relay for proper operation.
5
Examine the wiring harness for any signs of wear, fraying, or shorts.
6
Test the alternator output while the engine is running to check for adequate voltage.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II scanner
•Multimeter
•Basic socket set
•Wire brush
•Electrical contact cleaner

Parts Required

•Headlight bulbs (OEM or high-quality aftermarket)
•Headlight relay (if required)
•Alternator (if required)

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Symptoms

•Headlight flickering or dimming while driving

•Potential dashboard warning lights illuminated (e.g., battery or electrical system warning)

•Increased frequency of flickering with engine RPM changes

•Headlights turning off briefly and then back on

•Possible malfunctioning of other electrical components (e.g., radio, interior lights)

Diagnostic Steps

1
Scan the vehicle's OBD-II system for any error codes related to electrical systems.
2
Inspect the headlight bulbs for signs of corrosion or damage.
3
Check the battery voltage and connections to ensure they are secure and clean.
4
Inspect the headlight relay for proper operation.
5
Examine the wiring harness for any signs of wear, fraying, or shorts.
6
Test the alternator output while the engine is running to check for adequate voltage.

Solution

1. Preparation

Tools Required: OBD-II scanner, multimeter, basic socket set, wire brush, electrical contact cleaner.
Ensure the vehicle is parked on a flat surface with the engine off.
Disconnect the negative battery terminal to prevent electrical shocks.

2. Inspect and Replace Headlight Bulbs

Remove the headlight assembly by unscrewing the retaining screws and disconnecting the wiring harness.
Inspect the bulbs for any signs of damage or burnt filaments.
If necessary, replace with new bulbs:
- Ensure to use OEM or high-quality aftermarket bulbs for optimal performance.
- Follow the manufacturer's specifications for bulb type (e.g., H11, 9005).
Reassemble the headlight assembly and reconnect the wiring harness.

3. Check Battery and Wiring

Reconnect the negative battery terminal.
Use a multimeter to check battery voltage; it should be around 12.6 volts when the engine is off and 13.7-14.7 volts when running.
Clean battery terminals and cable connections with a wire brush and apply electrical contact cleaner.
Inspect the wiring harness for any visible damage, and repair or replace as needed.

4. Replace Headlight Relay

Locate the headlight relay in the fuse box (refer to the owner's manual for its exact location).
Remove the relay and test it with a multimeter for continuity.
If faulty, replace the relay with a new one, ensuring it is rated for the F-150.

5. Alternator Testing

Start the engine and connect a multimeter to the battery terminals.
Verify that the alternator is providing adequate voltage (13.7-14.7 volts).
If the voltage is low, consider replacing the alternator.