how to troubleshoot my Ford Mustang S650 (2024-Present) that won’t turn over in cold weather

Solution

1. Preparation

• Tools Needed: Multimeter, socket set, wire brush, torque wrench, fuse tester.
• Ensure the vehicle is in park or neutral with the parking brake engaged.
• Disconnect the battery negative terminal.

2. Battery Inspection and Replacement

• Sub-steps:
  1. Clean battery terminals and cable ends using a wire brush.
  2. If the battery voltage is low (below 12.4V), jump-start or charge the battery.
  3. If the battery fails to hold a charge, replace it with one that meets or exceeds the manufacturer's cold cranking amps (CCA) specification.
  4. Reconnect the battery terminals securely and check for tightness.

3. Starter Relay and Fuse Replacement

• Sub-steps:
  1. Locate the starter relay in the fuse box; use the vehicle's owner manual for reference.
  2. Remove the starter relay and test it for continuity with a multimeter.
  3. If the relay is faulty, replace it with a new one.
  4. Check the starter fuse for continuity; replace it if blown.

4. Ignition Switch and Ground Connection Check

• Sub-steps:
  1. Inspect the ignition switch; ensure it is functioning correctly by testing voltage at the starter terminal when the key is turned.
  2. Check the ground connections from the battery to the chassis and engine block for tightness and corrosion. Clean and tighten as necessary.

5. Final Assembly

• Reconnect the battery negative terminal.
• Ensure all components are secure and in place.