How to Fix Snowmobile Speedometer (12 Tips)

From mysterious sensor hiccups to wiring enigmas, snowmobile speedometer issues can arise at any time. You never want them to fail, especially on icy trails — where accurate speed readings are crucial to your safety and the optimal handling of your snow rig.

How do you fix a snowmobile speedometer? Fixing a snowmobile speedometer involves diagnosing sensor issues, checking wiring for damage, and ensuring proper connections. You may also need to replace faulty components, calibrate if needed, and conduct regular maintenance (among other things) for optimal performance in wintry conditions.

Steps vary based on the make and model of the snow machine and the type of speedometer it is equipped with. Nonetheless, here are 12 tips on how to fix a speedometer that generally applies to most snowmobiles.

1. Replace the affected speedometer cable.
2. Evaluate and test the magnet and speed sensor.
3. Inspect, clean, and lube electrical links.
4. Address wiring and circuit board issues.
5. Examine and repair gears.
6. Protect wiring from interferences and glitches.
7. Replace defective shear key and bearings.
8. Avert gear adapter issues with regular upkeep.
9. Run diagnostics to identify cluster faults.
10. Store your sled in a controlled environment.
11. Install shock-absorbing mounts and bolster fixtures.
12. Evaluate driveshaft damage and fix or swap as needed. 

How to Fix Snowmobile Speedometer

1. Replace the Affected Speedometer Cable.

The sole solution for a deteriorated snowmobile speedometer cable is to replace it. But before doing so, assess the cable’s overall condition, ascertaining any visible wear, kinks, or damage.

Ensure the cable is free from defects and is the correct size for your snow rig before installation. After which, test the cable’s functionality by attaching it to a drill and checking if the speedometer responds accurately.

2. Evaluate and Test the Magnet and Speed Sensor.

First, to address a defective magnet or snowmobile speed sensor, locate the latter and visually inspect for any visible damage or displacement. If damaged, replace as needed.

Ensure the new sensor is compatible and securely installed. After replacement, test the speedometer to confirm accurate speed readings, verifying the sensor is working as it should.

3. Inspect, Clean, and Lube Electrical Links.

To remedy corroded or loose electrical connections affecting your snowmobile speedometer, disconnect the battery to ensure safety. Inspect the connections for visible corrosion, cleaning them thoroughly with a wire brush or abrasive material.

After which, apply a specialized electrical contact cleaner to remove any remaining rust. Once cleaned, reconnect the connections securely and add dielectric grease or anti-corrosion compounds to prevent future issues. Following these steps, test the speedometer to confirm proper functionality.

4. Address Wiring and Circuit Board Issues.

If you have already disconnected the battery, address faults with the wiring or circuit board by inspecting them for visible damage, ensuring all connections are secure.

Repair or replace damaged sections (if any) using the tools and materials listed below. After the repair, reconnect the battery and test the speedometer to verify if the problem has been resolved.

Tools

• Screwdrivers (various sizes)
• Phillips screwdriver
• Pliers
• Wire stripper
• Fluke 289 True-RMS Stand Alone Logging Multimeter (view on Amazon) or similar multimeter
• Ohm meter
• Soldering iron and solder
• Heat shrink tubing or electrical tape
• Wire connectors and crimping tool
• Small brush or compressed air (for cleaning)
• Diagnostic software or service manual (snowmobile-specific)

Materials

• Replacement wires (if needed)
• Replacement circuit board (if needed)
• Electrical contact cleaner
• Dielectric grease
• Anti-corrosion compounds
• Replacement connectors (if needed)
• Heat shrink tubing or electrical tape
• Flux (for soldering, if applicable)
• Desoldering braid or pump (for soldering, if applicable)
• Safety equipment (gloves, safety glasses)

Some online sources and snowmobile-dedicated forums recommend using the pink eraser of a pencil to deep-clean connectors on the circuit board if using an electronic cleaner does not suffice.

Also, if there is a need for soldering certain sections, one best practice is first to try soldering on a spare, non-functioning plastic circuit board. Once you are confident, you can work directly on the circuit board.

5. Examine and Repair Gears.

To resolve speedometer issues related to gear and teeth problems, inspect and repair (or replace) damaged components after parking your snow rig on a stable surface and disconnecting the battery. Here is a more extensive breakdown of this process:

Step #1:

Locate the speed sensor (often positioned near the track or a driveshaft) and examine its gear teeth for wear, damage, or missing teeth. Replace as needed.

Step #2:

If applicable, inspect gears on the driveshaft or track drive connected to the speed sensor. Then, repair or replace damaged gears.

Step #3:

Check gears in the transmission for wear, misalignment, or damage. Ensure smooth rotation and proper alignment. Otherwise, address any transmission gear issues identified.

Step #4:

If the snowmobile has a belt or clutch system, scrutinize gears within these components and do what is needed.

Step #5:

Verify proper alignment of all drivetrain gears and correct misalignments.

Step #6:

Reconnect the battery and conduct a test to check the functionality of the speedometer, observing for consistent speed readings and smooth operation.

Step #7:

After all is set, record repairs and maintenance performed on your snowmobile. Note any recurring issues for future reference.

Regular maintenance — including checking gear conditions and alignments — can prevent speedometer malfunctions and is part of the process, too. However, if speedometer problems persist after ascertaining that gear and teeth are in good working condition, further diagnostics may be warranted.

6. Protect Wiring from Interferences and Glitches.

Addressing EMI (Electromagnetic Interference) and software glitches in snowmobile speedos involves several steps as follows:

Step #1:

Locate potential sources of interference, such as electronic devices, power lines, or other electrical components. Minimize the proximity of the speedometer wiring to these sources.

Step #2:

Use shielding materials, such as metallic wraps or conduits, to protect the speedometer wiring from external electromagnetic influences. Also, ensure proper grounding of the shielding to redirect and dissipate interference.

Step #3:

Assess wiring for any damage or wear that may contribute to signal disruption. Repair or replace damaged sections and secure wiring away from potential interference sources.

Step #4:

Install ferrite cores around the speedometer wiring to absorb and reduce high-frequency interference. Place them close to the speedometer and at potential interference entry points.

Step #5:

Check for updates for the speedometer’s control unit. Revert to the owner’s guidelines for instructions when performing software updates.

Step #6:

Isolate the speedometer wiring from other electronic components to prevent interference. For critical signals, use separate circuits or dedicated wiring paths.

Step #7:

Confirm that the snowmobile’s electrical system is properly grounded and address any grounding issues that may contribute to interference.

Step #8:

Mitigate the effects of external factors. Extreme temperatures or moisture can affect electronic components. As such, store your snow rig in a controlled environment during disuse to minimize potential issues.

Alongside these steps, refer to OEM guidelines for the snowmobile and speedometer. They should contain specific instructions on minimizing EMI and resolving software issues without the warranty being invalidated. However, if problems persist, seek help from an authorized service center or certified technician.

7. Replace the Defective Shear Key and Bearings.

A failing driveline to gear key bearing exhibits warning signs well before a complete breakdown. Detecting any vertical or horizontal play in the driveshaft, as well as unusual sounds emanating from the same region, are typically indicative of impending bearing failure. Similarly, a deteriorating PTO bearing can set off noises like grinding, whining, or rumbling.

When replacing the PTO bearing in a snowmobile’s chain case, removing the skid frame and tunnel is not always required. As long as the bearing comes off the shaft easily, fully loosening the track should allow access to the affected bearing. Note, however, that this latter scenario more seldomly occurs. Hence, it is best to know how to do both processes.

If it is merely an inspection you are carrying out, you can easily do this by removing the belt, secondary pulley, speedometer cable, and gear adapter. Wipe off the grease and examine the bearing — any signs of failure should be evident.

If you wish to proceed with bearing replacement as a DIY task, consult your owner’s manual and photograph the process for accurate reassembly. While at it, consider bearing carrier positions to avoid confusion during reinstallation.

Overlooking this detail can lead to the persistence of the bearing issue, as carriers with an offset position can also cause speedometer malfunction.

8. Avert Gear Adapter Issues With Regular Upkeep.

Filth and inadequate lubrication are the topmost triggers of gear adapter failure. That said, it is essential to keep the components tidy and well-lubricated. Routine maintenance that includes cleaning and lubrication will help prevent recurring issues and ensure optimal functionality of the gear adapter.

9. Run Diagnostics to Identify Cluster Faults.

Fixing a defective instrument cluster involves a systematic approach. Conduct a thorough diagnostic assessment to identify potential problem sources such as sensor malfunctions, wiring damage, or internal failures. 

Follow this with rectifying faulty components per OEM guidelines (using compatible replacement parts) and running a comprehensive test for readout accuracy before using your speedometer again.

10. Store Your Sled in a Controlled Environment.

Perhaps the only preventative solution in this guide, addressing snow and ice accumulation, is more sensible than dealing with its repercussions. One may think it is not as grave as the other root causes highlighted here. However, this notion cannot be further from the truth since snow and moisture target electrical components — known to wreak the most havoc on the integrity of snowmobile systems when compromised.

11. Install Shock-Absorbing Mounts and Bolster Fixtures.

Resolving vibration and impact-related issues with a snowmobile speedometer involves a combination of preventive measures and targeted repairs. The process entails installing shock-absorbing mounts to help minimize the impact of vibrations.

Inspecting and reinforcing the speedometer’s mounting points is ideal for secure and stable attachment to the snowmobile. Thorough, regular inspections of components, wirings, and connections are crucial to this maintenance routine.

12. Evaluate Driveshaft Damage and Fix or Swap as Needed.

To rectify a broken driveshaft:

1. Determine if repair or replacement is needed.
2. Obtain a compatible replacement driveshaft, ensuring it meets OEM specifications.
3. Install the new driveshaft carefully, securing it properly to maintain optimal functionality.
4. Conduct thorough testing (including a speedometer accuracy check) before returning to using the sled.

Different Types of Snowmobile Speedometers

Not all tips detailed above would universally apply to all kinds of snowmobile speedometers. Whether your speedometer is electronic or mechanical, you may only need to take away relevant processes.

It would help if you had a good grasp of these different speedometer types to determine which category your unit falls under and what procedural nuances must be considered.

All motorized vehicles have one of two types of speedometer — cable or electronic. Refer to my post on vehicle speedometers for more details. It is no different for snowmobiles.

Let us break them down into sub-categories.

1. Analog-Mechanical Speedometers

Of all the sub-categories, this speedo has the oldest technology. This type uses analog mechanisms with gears and a needle on the dial.

As the name suggests, they are mechanical but do not necessarily use a cable. Externally, they have a classic look and feel suitable for those who prefer vintage, analog displays.

2. GPS Speedometers

As the name implies, these speedometers use Global Positioning System (GPS) technology to determine a snowmobile’s speed. This means they calculate speed based on signals received from satellites.

Their technology makes them one of the most accurate in the market (if not the most accurate). These speeds are also robust because they are unaffected by cable wear or electronic malfunctions.

3. LCD or LED Display Speedometers

This electronic speedometer type utilizes modern LCD or LED technology for clear and customizable digital displays. It is often multifunctional, with loads of information presented digitally and allowances for various interface options.

Apart from snowmobiles, most modern motorcycles and other motorsport vehicles have this kind of speedometer factory-installed.

4. Smartphone-Integrated Speedometers

Also an electronic type, these speedometers are the most portable (not to mention most convenient) of the lot and are highly preferred by enthusiasts and young adult riders. They leverage smartphone apps that utilize the phone’s GPS and sensors for speed tracking.

Speed data is transmitted from the smartphone to a display mounted on the snowmobile. But while these variants are reliable, they may not be as accurate as full-on GPS speedometers.

Conclusion — How to Fix Snowmobile Speedometer

If the above steps are futile, consult a professional mechanic for a thorough diagnosis. Complex issues might require specialized tools or expertise.

Additionally, ensure your snowmobile is stored in a controlled environment to minimize environmental impact and further electrical malfunctions. Remember, a second opinion is invaluable in tackling snowmobile issues — including persistent speedometer challenges.