why does my BMW 5 Series G30/G31 (2017-2024) headlights flicker while driving?

Solution

1. Preparation

• Gather tools and safety equipment including gloves and safety goggles.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Battery Inspection

• Tools Required: Multimeter, battery terminal cleaner.
• Use the multimeter to check battery voltage; it should be around 12.6 volts when not running and 13.7-14.7 volts when the engine is running.
• Clean battery terminals and ensure they are tight; replace the battery if it is weak or failing.

3. Alternator Testing

• Tools Required: Multimeter.
• With the engine running, measure the voltage at the battery terminals; confirm it is within the proper range (13.7-14.7 volts).
• If the voltage is low, inspect the alternator belt for wear, and check connections to the alternator. Replace the alternator if faulty.

4. Headlight Inspection

• Tools Required: Socket set, replacement bulbs (if needed).
• Remove the headlight assembly by unscrewing the retaining screws and disconnecting the wiring harness.
• Inspect the bulbs for any signs of damage; replace if necessary.
• Check the connections in the headlight socket for corrosion or looseness.

5. Wiring and Relay Inspection

• Tools Required: Wire stripper, electrical tape, multimeter.
• Inspect the wiring harness for any signs of wear or damage; repair or replace as needed.
• Test the headlight relay by swapping it with a similar relay in the fuse box to see if the flickering resolves.