why does my Ford Mustang S650 (2024-Present) battery die when parked overnight

Solution

1. Preparation

• Tools Required: Multimeter, OBD-II scanner, basic hand tools (screwdrivers, pliers).
• Disconnect the negative battery terminal to ensure safety before working on electrical components.

2. Identify and Fix Parasitic Draw

1. Reconnect Multimeter: Reconnect the multimeter in series with the battery's negative terminal to measure current draw.
2. Monitor Current: Wait for the vehicle's systems to enter sleep mode (typically 30 minutes). Note the current draw.
3. Check Circuits: If the draw exceeds 50 milliamps, begin pulling fuses systematically to isolate the circuit causing the draw.
   • Document: Keep track of which fuses are removed and the corresponding current readings.
4. Resolve Issues: Once a problematic fuse is identified, inspect that circuit for faulty components or wiring issues. Replace or repair as necessary.

3. Test and Replace Battery (if needed)

1. Load Test: Using a load tester, apply a load to the battery to check if it can hold a charge.
2. Replace Battery: If the battery fails the load test, remove the old battery:
   • Disconnect the negative terminal first, then the positive.
   • Remove any retaining brackets and lift the battery out.
   • Install the new battery by reversing the removal steps.
   • Reconnect the positive terminal first, then the negative.