2020 CAT 279D3 Skid Steer No Power to Glow Plugs Troubleshooting

[MikePhua]

A user on the Panswork forum encountered an issue with their 2020 CAT 279D3 skid steer, where the machine failed to start, and the "no power to glow plugs" error appeared. This problem prevented the engine from starting properly, especially in colder weather, as the glow plugs were not receiving the necessary power to function.
Potential Causes for No Power to Glow Plugs:

1. Glow Plug Control Circuit Malfunction:
   Glow plugs receive power through a control circuit. If there is an issue within this circuit—such as a blown fuse, a faulty relay, or loose wiring—the glow plugs will not get the power they need, leading to startup issues.
   
2. Ignition System Failure:
   The ignition system usually provides the power to the glow plugs via a control module or a start relay. If there is an issue with the ignition system, such as a faulty control module or relay, the glow plugs will not receive the required power to initiate the starting process.
   
3. Blown Fuse or Faulty Relay:
   The fuses or relays connected to the glow plug circuit could also be the source of the issue. If the fuse is blown or the relay fails to operate properly, the power will be interrupted, and the glow plugs will not function.
   
4. Loose or Shorted Wiring:
   Loose or damaged wiring can also prevent proper power flow to the glow plugs. If the connections are poor or the wires are shorted, the power supply to the glow plugs may be disrupted, preventing them from functioning.
   

Troubleshooting Steps:

1. Check Fuses and Relays:
   The first step is to check the fuses and relays related to the glow plug circuit. Refer to the machine’s manual to locate the fuses and check for any blown fuses. If any fuses are blown, replace them. If the relay is faulty, it will need to be replaced as well.
   
2. Inspect Electrical Wiring:
   Carefully inspect the wiring connected to the glow plugs. Ensure that all connections are secure, and check for any signs of wear or corrosion. If any loose connections are found, they should be reattached or cleaned. Look for any damaged wires or short circuits that might be interrupting the power flow.
   
3. Test the Control Module:
   If the fuses, relays, and wiring are all in good condition, the problem may lie with the control module. Use a diagnostic tool to check the control module’s functionality and ensure it is properly sending power to the glow plugs.
   
4. Check the Start Relay:
   The start relay is responsible for providing power to the glow plugs. Ensure that the relay is functioning properly and making the necessary connections. If the relay is faulty, replace it with a new one.
   
5. Check Battery Voltage:
   Low battery voltage can affect the entire electrical system, including the glow plugs. Check the battery’s voltage to ensure it is sufficiently charged. If the battery voltage is too low, the system may fail to power the glow plugs, making it harder to start the engine.
   

Solutions:

1. Replace Blown Fuses or Faulty Relays:
   If the fuses are blown or the relay is malfunctioning, replace them with original factory parts to restore the power supply to the glow plugs.
   
2. Repair Electrical Connections:
   Re-secure any loose connections, clean the contact points, and replace any worn or damaged wires to restore proper electrical contact.
   
3. Replace Faulty Control Module:
   If the control module is determined to be faulty, it will need to be replaced to ensure that the glow plugs receive the correct power supply.
   
4. Replace the Battery:
   If the battery is found to be weak or undercharged, replace it with a fully charged one to ensure that the system has enough power for the glow plugs and starting system to function correctly.
   

Preventive Measures:

1. Regular Electrical System Inspections:
   Periodically check the fuses, relays, and electrical wiring connected to the glow plugs to ensure they are in good working condition. This can help identify potential issues before they cause problems with the engine start.
   
2. Use a Suitable Battery:
   Make sure the battery has enough capacity to handle the power needs of the machine, especially in colder temperatures. A weak or old battery can struggle to provide the necessary power for the glow plugs and other starting components.
   
3. Routine Maintenance:
   Regular maintenance of the electrical and ignition systems, as well as the overall engine, will help prevent issues with starting, particularly in cold weather. Early identification and repair of electrical issues can avoid unexpected downtime.
   

Conclusion:
The issue of "no power to glow plugs" in the 2020 CAT 279D3 skid steer is likely due to electrical system faults. By checking and replacing fuses, relays, inspecting wiring, testing the control module, and ensuring proper battery voltage, the issue can be effectively diagnosed and resolved. Regular inspections and maintenance of the electrical system will help prevent similar issues from occurring in the future, ensuring the machine starts reliably even in colder conditions.