why does my Volkswagen Golf MK7 (2015-2019) battery die when the car is off

Solution

1. Preparation

• Tools Required: Multimeter, OBD-II scanner, socket set, basic hand tools.
• Safety Warnings: Disconnect the negative battery terminal before working on electrical systems.

2. Replace Faulty Battery

1. Remove the Battery:
   • Disconnect negative terminal first, followed by the positive terminal.
   • Remove any brackets or covers securing the battery in place.
   • Carefully lift the battery out of the tray.
2. Install New Battery:
   • Place the new battery in the tray.
   • Secure it with brackets.
   • Connect the positive terminal first, followed by the negative terminal.

3. Address Parasitic Draw

1. Identify the Faulty Circuit:
   • Reconnect the battery and measure the parasitic draw with the multimeter.
   • Remove the fuses one by one until the draw drops to an acceptable level.
2. Repair or Replace Components:
   • Inspect and repair any damaged wiring or connectors in the offending circuit.
   • Replace any faulty components (e.g., module, switch) that are causing the draw.

4. Verify Charging System

1. Test Alternator:
   • With the engine running, check the voltage at the battery terminals.
   • If the voltage is outside the normal range, consider replacing the alternator.