How do you adjust the speedometer on a Ford F-150?

Before beginning, gather the following tools:

1. Flathead screwdriver.
2. Phillips-head screwdriver.
3. Adjustable wrench.
4. Digital Multimeter.
5. A computer with internet access to access the latest speedometer recalibration codes for your vehicle model and year.

Step 2: Preparation

1. Turn off the engine and let the vehicle cool down.
2. Engage the parking brake.
3. Locate the vehicle's OBD-II (on-board diagnostics) port under the dashboard, usually near the steering wheel.
4. Open the hood and connect the positive and negative leads of the digital multimeter to the battery's positive (+) and negative (-) terminals, respectively. Turn on the multimeter.

Step 3: Adjusting the Speedometer

1. Connect your scanner to the OBD-II port.
2. Turn the ignition switch to position 2, without starting the engine. The multimeter should display a voltage of approximately 12 volts.
3. Use the flathead screwdriver to pry open the instrument cluster housing (the panel containing the speedometer).
4. Locate the speedometer module. It's usually a round or square device behind the speedometer gauge.
5. Use the Phillips screwdriver to remove the screws securing the speedometer module.
6. Once removed, locate the trim potentiometer on the speedometer module. This is a small adjustable screw or dial used to fine-tune the speedometer.
7. Turn the trim potentiometer gently with a small flat-head screwdriver to calibrate the speedometer. Typically, turning it clockwise increases the speedometer reading, while turning counterclockwise decreases it
8. Test the speedometer by starting the engine and driving at a known speed. Use your digital multimeter or GPS speedometer app to verify if the speedometer is accurate at various speeds.

Step 4: Finalizing the Adjustment

1. If the speedometer is correctly calibrated, reinsert the speedometer module into the instrument cluster and secure it with the screws you removed earlier.
2. Put the instrument cluster housing back in place and secure it with the pry marks.

_Note: For some Ford F-150 models, you might need to access a digital speedometer calibration tool or a code from a Ford dealership to perform this adjustment._