Case IH 7024 – INST: Reversible Fan Control open circuit or shorted to ground

The controller is detecting that the electrical path to the fan's control relay or hydraulic solenoid is either broken/disconnected (open circuit) or the hot wire is touching the chassis/ground (shorted to ground).

• MX Magnum
• Magnum
• Puma
• Steiger
• Optum
• Vestrum
• Farmall
• Farmlift 635
• Farmlift 735
• Farmlift 935
• 521F

1. 1

   Check the reversible fan control relay in the main fuse/relay box for internal failure or swap it with a known-good identical micro relay.

2. 2

   Visually inspect the wiring harness running from the cab/instrumentation controller to the reversible fan relay, and from the relay to the fan control solenoid for chafed wires, melted insulation, or disconnected plugs.

3. 3

   Disconnect the fan control solenoid and measure the resistance across the solenoid pins; an open line (OL) or zero ohms indicates the solenoid has internally failed.

4. 4

   Check the signal wire from the INST controller to the solenoid for continuity to ground while unplugged to verify if the wire is shorted to the chassis.

5. 5

   Verify that the fuse supplying power to the reversible fan circuit is not blown (a blown fuse is a strong indicator of a short to ground).

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Relay Replacement

   If the diagnostic tests point to a failed relay (common issue), remove the faulty micro relay from the fuse panel and install a new 12V 20A diode-protected relay.

3. 3

   Wiring Repair

   If a short or break was found in the harness, cut out the damaged section of wiring. Splice in new wire using weather-sealed heat-shrink butt connectors. Secure the harness away from hot engine components or sharp edges using zip ties or loom.

4. 4

   Solenoid/Valve Replacement

   If the fan control valve/solenoid is internally shorted or open, relieve hydraulic pressure (if applicable), disconnect the electrical connector, unthread the faulty solenoid from the manifold or fan drive, and install the replacement part.

5. 5

   Reassembly and Clearing

   Reconnect the battery. Turn the ignition on and use the instrument cluster or a diagnostic tool to clear the INST 7024 fault code.

6. 6

   Verification

   Start the engine and manually trigger the reversible fan function via the cab switch or display to ensure the fan reverses pitch/direction without throwing the code again.