my Toyota Corolla E140 (2006-2013) headlights keep flickering

Solution

1. Preparation

• Tools Required: Multimeter, socket set, OBD-II scanner, basic hand tools.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Clean Battery Connections

• Remove the battery terminals (negative first, then positive).
• Clean the terminals and battery posts with a wire brush or battery cleaning solution.
• Reconnect the terminals securely (positive first, then negative).

3. Replace Headlight Relay

• Locate the headlight relay in the fuse box (refer to the owner’s manual for exact location).
• Using a socket set, remove the relay from its socket.
• Install a new relay of the same specifications.

4. Inspect and Repair Wiring

• Visually inspect the wiring harness leading to the headlights for any signs of damage.
• If damaged wires are found, repair using electrical tape or replace the affected sections of the harness.

5. Test and Replace Alternator (if necessary)

• If alternator output is below 13.5V, consider replacing the alternator.
• Remove the old alternator by disconnecting the battery, removing the belt, and unbolting the alternator.
• Install the new alternator, reconnect the battery, and check output voltage again.