why does my Toyota Highlander Third Generation (2014-2019) have a weak battery

Solution

1. Preparation

• Gather necessary tools: multimeter, battery terminal cleaner, socket set, and safety gloves.
• Ensure the vehicle is parked on a flat surface and the engine is off.

2. Battery Inspection

• Sub-step 1: Disconnect the negative terminal first, followed by the positive terminal to prevent short circuits.
• Sub-step 2: Clean the battery terminals using a terminal cleaner to remove any corrosion.
• Sub-step 3: Reconnect the terminals securely, starting with the positive terminal, then the negative terminal.

3. Battery Replacement (if necessary)

• Sub-step 1: Remove the battery hold-down clamp using a socket set.
• Sub-step 2: Carefully lift the old battery out of the battery tray, ensuring to maintain a stable grip.
• Sub-step 3: Place the new battery in the tray, ensuring it’s oriented correctly.
• Sub-step 4: Reattach the hold-down clamp and tighten it to secure the battery.
• Sub-step 5: Reconnect the positive terminal first, then the negative terminal.

4. Alternator Testing

• Sub-step 1: Start the engine and use a multimeter to check the alternator output; it should be between 13.8 to 14.5 volts.
• Sub-step 2: If the output is low, consider replacing the alternator.