New Holland INST 7024 – INST: Reversible Fan Control open circuit or shorted to ground

This indicates a circuit failure in the system that controls the reversible engine cooling fan. The fan is designed to reverse its blade pitch or rotation to blow out dust and debris from the radiators. The system has detected that the electrical circuit commanding this function is either broken (open circuit) or has a bare wire touching the machine's chassis (shorted to ground), preventing the fan from reversing.

• New Holland T7 Series (e.g., T7.220, T7.250)
• New Holland T8 Series (e.g., T8040)
• New Holland T9 Series
• New Holland TVT Series
• New Holland LM Series (e.g., LM7.42, LM9.35)

1. 1

   Check the Fuse and Relay: Inspect the specific fuse and relay assigned to the reversible fan. For example, on T8000 series tractors, this is often Fuse 28 (20 Amp) and its associated micro-relay.

2. 2

   Inspect the Wiring Harness: Visually inspect the wiring harness leading to the fan control solenoid or the fan's pneumatic compressor for chafing, melted insulation, or disconnected plugs.

3. 3

   Test the Solenoid/Motor: Depending on the system (hydraulic motor or Cleanfix pneumatic variable-pitch fan), test the control solenoid or the small electric air compressor motor for continuity. An infinite resistance reading means the coil/motor is open and has failed.

4. 4

   Check the Ground: Verify that the ground connection for the reversible fan circuit is clean, tight, and free of corrosion.

1. 1

   Power Down

   Turn off the machine, remove the key, and locate the main fuse/relay distribution box.

2. 2

   Verify Power Supply

   Test the reversible fan fuse and relay. If the fuse is blown, it confirms a short to ground. Replace the fuse/relay if faulty.

3. 3

   Harness Testing

   Disconnect the wiring harness at the reversible fan control solenoid (or compressor). Use a digital multimeter to check for continuity between the instrument cluster output and the fan connector.

4. 4

   Locate the Short/Open

   If continuity is broken or if the power wire shows continuity to the chassis ground, trace the harness along the engine block and cooling package to find the damaged section. Repair or replace the wiring harness.

5. 5

   Test the Actuator

   Measure the resistance across the pins of the fan control solenoid. If it reads out of specification (open circuit or dead short), replace the solenoid valve or compressor unit.

6. 6

   Reassembly and Clearing

   Reconnect all plugs, ensuring they are seated and locked. Turn the ignition on, clear the INST 7024 fault code via the instrument cluster or diagnostic tool, and press the "Fan Reversal" button in the cab to verify the fan cycles correctly.