Inboard Boat Speedometer Not Working: Troubleshooting Tips For 2023

How to Fix Boat Speedometer Simple Method YouTube
How to Fix Boat Speedometer Simple Method YouTube from


Inboard boats are a popular choice for water enthusiasts, offering power and performance. However, one common issue that boat owners may encounter is a speedometer that stops working. This can be frustrating, as it hinders your ability to accurately measure your boat’s speed. In this article, we will explore some troubleshooting tips to help you diagnose and fix the problem.

1. Check the Connections

The first step in troubleshooting a non-functional speedometer is to check the connections. Start by inspecting the wiring harness and ensure that it is securely connected to both the speedometer and the boat’s power supply. Look for any loose or corroded connections, and clean or tighten them as necessary.

2. Inspect the Speed Sensor

The speed sensor is responsible for detecting the boat’s speed and sending the information to the speedometer. Locate the speed sensor, typically located on the boat’s transom or lower unit. Check for any damage, such as loose wires or debris obstructing the sensor. Clean the sensor and ensure it is properly aligned with the boat’s propeller.

3. Test the Speedometer

If the connections and speed sensor appear to be in good condition, the next step is to test the speedometer itself. Disconnect the wiring harness from the speedometer and use a multimeter to check for continuity. If there is no continuity, it may indicate a faulty speedometer that needs to be replaced.

4. Verify the Power Supply

Ensure that the boat’s power supply is providing sufficient voltage to the speedometer. Use a multimeter to measure the voltage at the speedometer’s connection. If the voltage is below the required range, check the boat’s battery and charging system for any issues.

5. Consider Interference

Interference from other electronic devices or wiring can affect the speedometer’s accuracy. Ensure that the speedometer wiring is separate from any other wiring, especially those carrying high currents. Additionally, check for any electronic devices that may be causing interference and relocate them if necessary.

6. Check for Water Damage

Boating exposes your equipment to water, and speedometers are no exception. Inspect the speedometer for any signs of water damage, such as fogged or hazy displays. Water damage can affect the internal components and cause the speedometer to malfunction. If water damage is present, consider replacing the speedometer.

7. Consult the Owner’s Manual

If you have tried the above steps and the speedometer still does not work, consult the owner’s manual. The manual may provide specific troubleshooting steps or information on how to reset the speedometer. It may also offer guidance on how to contact the manufacturer or a certified technician for further assistance.

8. Consider Professional Help

If all else fails, it may be time to seek professional help. A certified marine technician will have the expertise and tools to diagnose and repair the speedometer issue. They can also ensure that other components of your boat’s electrical system are in good working order.


A non-functional speedometer can be a frustrating issue for boaters. By following these troubleshooting tips, you can identify and resolve the problem, ensuring that your inboard boat’s speedometer is working properly. Remember to always prioritize safety and consult a professional if needed. Now, you can enjoy your time on the water with confidence in your boat’s speed measurements.