why does my Volkswagen Golf MK7.5 (2020-Present) battery light keep coming on

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Clean Battery Connections

• Tools Required: Wire brush, battery terminal cleaner
• Remove any corrosion from the battery terminals using a wire brush and battery terminal cleaner.
• Ensure the connections are tight and secure. Reconnect the negative terminal.

3. Test and Replace the Battery (if necessary)

• Tools Required: Multimeter
• If the battery voltage is below 12.4V, replace the battery.
  • Disconnect the battery (negative first, then positive).
  • Install the new battery by connecting the positive terminal first, followed by the negative terminal.
  • Ensure the connections are tight.

4. Test and Replace the Alternator (if necessary)

• Tools Required: Socket set, torque wrench
• If the alternator is not providing the correct output:
  • Disconnect the battery again.
  • Remove the serpentine belt by loosening the tensioner.
  • Disconnect the wiring harness from the alternator.
  • Remove the alternator mounting bolts and take out the alternator.
  • Install the new alternator by reversing the removal process, ensuring to torque bolts to manufacturer specifications (typically around 37 ft-lbs).
  • Reconnect the battery.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and monitor the dashboard for warning lights.
• Check the voltage at the battery with the engine running to ensure proper alternator output.