why does my Honda Civic has a battery light on while driving

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, multimeter, socket set, replacement battery or alternator (if needed).
• Disconnect the negative battery cable to ensure safety during repair.

2. Battery Inspection

• Remove the battery cover if applicable.
• Clean any corrosion from the terminals using a wire brush and baking soda solution.
• Test the battery's voltage with a multimeter; replace if voltage is below 12.4 volts.

3. Alternator Testing

• Reconnect the battery and start the engine.
• Use a multimeter to check the voltage at the alternator output terminal; it should be between 13.8 and 14.5 volts.
• If the output is low, proceed to replace the alternator.

4. Alternator Replacement

• Disconnect the battery (negative terminal).
• Remove the serpentine belt by loosening the tensioner pulley.
• Unbolt the alternator from its mount using the socket set.
• Disconnect the electrical connectors from the alternator.
• Install the new alternator by reversing the removal steps.
• Reinstall the serpentine belt, ensuring proper routing and tension.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and check for the battery light.
• Verify that the voltage output from the alternator is within the specified range again.