my Volkswagen Golf MK5 (2004-2008) won't start and just clicks, what should I check?

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, wrench set, screwdriver set, and jumper cables.
• Ensure the vehicle is in park (automatic) or neutral (manual).
• Disconnect the negative battery cable for safety.

2. Battery Inspection and Replacement

1. Inspect the Battery
   • Clean corrosion from battery terminals using a wire brush.
   • Tighten any loose connections.
2. Test Battery Health
   • Use a multimeter to check battery voltage.
   • If voltage is below 12.4 volts, recharge or replace the battery.
3. Replace Battery (if necessary)
   • Remove the negative terminal first, followed by the positive terminal.
   • Remove the battery hold-down bracket and lift out the battery.
   • Place the new battery in the tray, secure it with the hold-down bracket.
   • Connect the positive terminal first, followed by the negative terminal.

3. Starter Inspection and Replacement

1. Check Starter Connections
   • Inspect the wiring to the starter for damage or loose connections.
   • Ensure the starter solenoid connection is secure.
2. Remove the Starter
   • Disconnect the battery again for safety.
   • Remove any components blocking access to the starter (e.g., intake duct).
   • Unbolt the starter from the engine block using the appropriate wrench.
3. Test or Replace Starter
   • Bench test the starter by applying direct battery voltage to see if it engages.
   • If the starter fails the test, replace it with a new or refurbished unit.
4. Reinstall Starter
   • Position the new starter and bolt it in place securely.
   • Reconnect any components removed during disassembly.