Bobcat 873 C Hour Meter Not Counting: Troubleshooting and Solutions

[MikePhua]

The Bobcat 873 C is a powerful and reliable skid steer loader known for its durability and performance in various applications, including construction, landscaping, and demolition. One of the critical components for managing a machine's usage and maintenance intervals is the hour meter. It records the number of hours the equipment has been in operation, helping operators and fleet managers track wear and tear, plan maintenance, and monitor overall machine health. However, if the hour meter stops counting, it can pose a significant challenge in keeping the machine properly serviced. This article explores the potential causes of a non-functioning hour meter in the Bobcat 873 C and offers troubleshooting and solutions to restore its function.
Understanding the Role of the Hour Meter
Before diving into troubleshooting, it’s important to understand the purpose of the hour meter. The hour meter is an electronic gauge that keeps track of how long a machine has been in use. It plays a crucial role in maintaining equipment by:

• Tracking Maintenance Intervals: Regular servicing is based on the number of operating hours. The hour meter helps determine when oil changes, fluid replacements, and inspections are due.
  
• Monitoring Wear and Tear: The meter provides data that helps operators assess how much wear the equipment has endured. Over time, heavy machinery components like the engine, hydraulic systems, and drive motors begin to show signs of stress, and timely maintenance can prevent premature failure.
  
• Estimating Resale Value: For used equipment, the hour meter is a key factor in determining the resale price. Machines with lower operating hours generally hold more value.
  

When the hour meter stops functioning, you lose these benefits and risk missing important maintenance tasks.
Symptoms of a Non-Functioning Hour Meter
If the hour meter on your Bobcat 873 C is not counting, there are several symptoms to look for that can help you identify the underlying problem:

• The display is blank or frozen: The hour meter’s screen may be completely blank, or the hours may remain stuck at a certain number.
  
• Intermittent operation: Sometimes the hour meter may work intermittently, counting hours only when the machine is in certain positions or during specific activities.
  
• No response when the machine is running: The hour meter does not increase as the machine operates, even though the engine and other systems are functional.
  

These symptoms point to an issue with the hour meter's ability to track or display running time.
Potential Causes of a Non-Functioning Hour Meter
There are several reasons why the hour meter on a Bobcat 873 C may stop counting. Understanding these causes will help you narrow down the problem and apply the correct solution.
1. Faulty Hour Meter Display
The most obvious cause of a non-functional hour meter is a problem with the display itself. Over time, the hour meter’s electrical components can wear out or suffer from issues like poor soldering, broken connections, or electrical shorts. If the display is not functioning correctly, it won’t be able to show the number of operating hours.

• Signs: A completely blank display or erratic behavior of the numbers.
  
• Solution: If the display itself is malfunctioning, the best option may be to replace the entire hour meter unit.
  

2. Faulty Hour Meter Sensor (Tachometer)
The hour meter in a Bobcat 873 C is typically triggered by a tachometer signal that monitors the engine's RPM. The tachometer detects the engine's rotation and sends a pulse to the hour meter, which then converts that signal into hours of operation. If the tachometer sensor is damaged, it might fail to send the signal necessary to activate the hour meter.

• Signs: The hour meter does not count, even though the engine is running.
  
• Solution: Inspect the tachometer sensor for any signs of wear or damage. Replace the sensor if needed. Make sure all connections are secure and free of corrosion.
  

3. Electrical Connection Issues
Loose or corroded electrical connections between the hour meter, tachometer, and the engine control unit (ECU) can also cause the hour meter to stop counting. These connections are crucial for transmitting signals from the tachometer to the hour meter, so any disruptions in these circuits can result in a malfunctioning meter.

• Signs: Unstable hour meter reading or the meter being completely frozen.
  
• Solution: Check all wiring connections, particularly those running to and from the hour meter. Inspect for any visible damage, corrosion, or loose connections. Repair or replace any faulty wiring as needed.
  

4. Faulty Engine Control Unit (ECU)
The engine control unit (ECU) manages several functions in modern machinery, including controlling the signals sent to the hour meter. If the ECU experiences issues, it may fail to send the necessary signals to the hour meter, causing it to stop working.

• Signs: The hour meter fails to count, even when all other components appear functional.
  
• Solution: Have the ECU diagnosed by a qualified technician. If the ECU is malfunctioning, it may need to be reset or replaced.
  

5. Failing or Incorrectly Installed Hour Meter Fuse
A blown fuse or faulty electrical relay that powers the hour meter can be a simple but easily overlooked cause of failure. The fuse or relay provides the necessary power to the hour meter, and if either fails, the meter will stop functioning.

• Signs: No power to the hour meter, or intermittent functionality.
  
• Solution: Inspect the hour meter’s fuse and relay, ensuring that they are intact and working properly. Replace the fuse if blown or test the relay for continuity.
  

How to Troubleshoot a Non-Functioning Hour Meter
To troubleshoot the issue effectively, follow these steps:

1. Inspect the Display: Begin by checking the hour meter’s display. If the display is completely blank, consider replacing the meter. If the numbers freeze or behave erratically, there may be an issue with the internal components.
   
2. Check the Tachometer Sensor: The tachometer is the most likely culprit for a failure to send the signal. Check the sensor’s connection to the engine and replace it if necessary.
   
3. Inspect the Wiring and Connections: Look for any loose or corroded wires that could disrupt the signal between the tachometer and the hour meter. Clean or replace any damaged wiring.
   
4. Test the Fuse and Relay: Check the fuse and relay that powers the hour meter. Replace the fuse if it’s blown, or test the relay for continuity.
   
5. Consult the ECU: If all else fails, the issue may lie with the ECU. Consult a professional mechanic to diagnose and repair any potential ECU issues.
   

Preventing Future Hour Meter Problems
To avoid issues with the hour meter in the future, it's essential to perform regular maintenance checks. Here are some tips:

• Regularly check the hour meter's functionality: Monitor the hour meter to ensure it’s working properly at regular intervals, especially after long periods of use.
  
• Keep electrical connections clean and secure: Regularly inspect and clean the wiring and connections to prevent corrosion and wear.
  
• Use proper maintenance practices: Always use high-quality fuel and lubricants, and follow the manufacturer's maintenance schedule for your Bobcat 873 C to ensure all systems, including the hour meter, function correctly.
  

Conclusion
A malfunctioning hour meter on a Bobcat 873 C skid steer loader can lead to difficulties in tracking maintenance schedules and overall machine performance. By understanding the potential causes, from faulty displays to sensor issues, and following a systematic troubleshooting approach, operators can resolve the problem and restore the functionality of the hour meter. Regular maintenance, including checks of electrical connections and sensors, will help prevent future issues and keep the Bobcat 873 C running efficiently for years to come.