how to fix my Toyota Corolla E140 (2006-2013) headlights flickering at night

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on the electrical system.

2. Inspect and Replace Bulbs

• Remove the headlight assembly by unscrewing the retaining screws.
• Disconnect the electrical connector from the bulb.
• Remove the bulb and inspect for any signs of damage.
• Replace with a new bulb if necessary, ensuring it matches the specifications (H11 for low beam, H9 for high beam).

3. Check Battery and Alternator

• Reconnect the battery terminal and use a multimeter to measure battery voltage.
• Start the engine and measure the alternator output at the battery terminals.
• If the alternator is not within the specified voltage, replace it with a new one following the manufacturer's specifications.

4. Inspect Wiring and Grounds

• Visually inspect the wiring harness for any signs of fraying or damage.
• Clean any corroded connections using a wire brush and apply dielectric grease to prevent future corrosion.
• Ensure that the ground connections for the headlights are secure and free of corrosion; tighten or replace as necessary.

5. Reassemble Headlight Assembly

• Reconnect the electrical connectors and secure the headlight assembly back into place.
• Reattach the retaining screws properly.