what causes the battery light to come on in my Volkswagen Tiguan First Generation (2007-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, serpentine belt tool.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Clean Battery Terminals

• Remove the battery terminal bolts and disconnect the terminals.
• Clean any corrosion using a wire brush and a mixture of baking soda and water.
• Reconnect the terminals securely and ensure they are tight.

3. Test and Replace Battery (if necessary)

• Tools Required: Battery tester.
• If the battery voltage is below 12.4 volts after testing, consider replacing the battery.
• Disconnect the old battery and install the new one, connecting the positive terminal first, followed by the negative.

4. Inspect and Replace Alternator (if necessary)

• Tools Required: Socket set, torque wrench.
• Remove the serpentine belt by loosening the tensioner using the serpentine belt tool.
• Disconnect the electrical connectors and mounting bolts from the alternator.
• Install the new alternator, securing it with the bolts to the specified torque.
• Reconnect the electrical connectors and reinstall the serpentine belt.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and check the battery voltage again to ensure it is within the proper range.