why does my Ford F-150 Fourteenth Generation (2021-present) battery die when parked overnight

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, multimeter, wrench set, battery terminal cleaner, and replacement battery (if needed).
• Ensure the vehicle is parked on a level surface with the engine off and keys removed.

2. Perform Parasitic Draw Test

• Disconnect the negative terminal of the battery.
• Connect the multimeter in series between the negative battery terminal and the negative cable.
• Note the current reading; it should be below 50mA. If it exceeds this, identify the source of the draw by pulling fuses one at a time and monitoring the current.

3. Clean Battery Terminals

• Use a wire brush or terminal cleaner to remove any corrosion from the battery terminals.
• Ensure the connections are clean and tight, then reconnect the terminals.

4. Replace Faulty Components

• If a component is identified as the source of the parasitic draw, replace it as necessary. For example, if a malfunctioning relay or switch is causing the issue, replace it according to the manufacturer’s specifications.
• If the battery is found to be weak or dead, replace it with a new, compatible battery (typically a Group 65 or equivalent).

5. Test Alternator Output

• With the engine running, use the multimeter to measure the voltage at the battery terminals. It should read between 13.7V and 14.7V.
• If the voltage is outside this range, diagnose and replace the alternator if it is not functioning properly.