CAT 252 Won’t Start - Electrical Issues Troubleshooting

[MikePhua]

Introduction to the Problem
A common issue faced by owners of the CAT 252 skid steer is that the machine refuses to start due to electrical malfunctions. The problem may not be immediately obvious, and various components could be contributing to the failure. Understanding the symptoms and performing methodical troubleshooting can help diagnose the issue and get the machine running again.
Symptoms of the Electrical Issue
When the CAT 252 fails to start, the operator may notice one or more of the following symptoms:

• No Power at All: The machine shows no signs of life when attempting to start, such as no lights or sounds when turning the key.
  
• Weak or No Cranking: When the key is turned, the machine may make a clicking sound or may not crank at all, indicating a possible issue with the starter or battery.
  
• Intermittent Power: In some cases, the machine may start but then shut down unexpectedly, which could indicate wiring problems or issues with the electrical connections.
  

Troubleshooting the Electrical Issue

1. Check the Battery and Battery Connections
   The first step in troubleshooting electrical issues is to check the battery. Ensure the battery is fully charged and that the terminals are clean and tight. Corroded or loose battery terminals can prevent the machine from starting.
   • Test the battery voltage using a multimeter. It should read around 12.6V when fully charged.
     
   • Inspect the battery cables for wear or damage.
     
   • If the battery is old or unable to hold a charge, replacing it could resolve the issue.
     
2. Examine the Starter and Solenoid
   If the battery appears fine, the next step is to check the starter and solenoid. If the starter motor isn’t engaging properly, the machine may fail to start.
   • Listen for a clicking sound when attempting to start. If you hear a click but the starter doesn’t turn over, the solenoid may be faulty.
     
   • Test the solenoid with a multimeter to ensure it's providing the necessary voltage to the starter.
     
   • Inspect the wiring leading to the starter for any visible damage or loose connections.
     
3. Inspect the Fuses and Relays
   Blown fuses or faulty relays can also prevent the machine from starting. Check the fuse box and replace any blown fuses. Refer to the user manual for the correct fuse ratings.
   • Inspect relays for signs of wear or damage. You can swap relays to see if that resolves the issue.
     
   • Check for continuity using a multimeter to ensure that each relay is functioning properly.
     
4. Check the Safety Interlock System
   The CAT 252 is equipped with a safety interlock system that prevents the machine from starting under unsafe conditions (e.g., if the seatbelt isn’t fastened or if the operator isn’t seated). Make sure all safety switches and sensors are functioning correctly.
   • Inspect the seat safety switch, brake interlock switch, and other sensors for signs of wear or malfunction.
     
   • Check the wiring to these sensors to ensure they are properly connected and free of damage.
     
5. Inspect the Ground Connections
   A poor ground connection can lead to electrical issues. Inspect all ground cables and ensure they are securely connected to the chassis.
   • Clean the grounding points to ensure a good connection.
     
   • If the ground connections are corroded or loose, repairing or replacing them could resolve the problem.
     
6. Examine the Ignition Switch and Wiring
   If the above steps don’t resolve the issue, the problem may lie within the ignition switch or the wiring itself.
   • Test the ignition switch to ensure it’s sending power to the necessary circuits when turned.
     
   • Inspect the wiring from the ignition switch to the starter, battery, and solenoid to ensure no wires are shorted or damaged.
     

Conclusion
Electrical issues are a common reason why the CAT 252 skid steer fails to start. By systematically checking the battery, starter, solenoid, fuses, relays, safety interlocks, and ground connections, you can usually identify and fix the issue. Regular maintenance and attention to the machine’s electrical system will help prevent future problems and ensure your equipment is ready to go when you need it.