Massey Ferguson 10.03.10 – AIRCON: Air Conditioning Evaporator Temperature Sensor Short Circuit

The controller is seeing a voltage or resistance value that is out of the expected range (typically near zero ohms or zero volts), meaning the sensor's internal wiring has failed, or the signal wire is shorted directly to ground or another voltage source in the harness.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Visually inspect the HVAC unit wiring harness (typically in the cab roof) for pinched wires, chafing against the metal frame, or melted insulation.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, moisture ingress, or bent terminals bridging the connection.

3. 3

   Perform a sensor resistance test using a multimeter across the disconnected sensor pins. A reading near 0 ohms indicates an internal short and requires replacement.

4. 4

   Perform a harness short-to-ground test by measuring resistance between the sensor signal wire (harness side) and a known good chassis ground. Continuity indicates a shorted harness.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the HVAC Unit

   Remove the cab roof panel or the specific interior trim panels required to access the A/C evaporator housing.

3. 3

   Locate the Sensor

   Find the evaporator temperature sensor. It is typically a probe inserted directly into the fins of the evaporator core.

4. 4

   Remove the Faulty Sensor

   Unplug the electrical connector. Carefully pull the sensor probe straight out of the evaporator fins. Do not use excessive force that could damage the delicate aluminum fins or tubes of the evaporator.

5. 5

   Install the New Sensor

   Gently insert the new sensor probe into the exact same location in the evaporator core. Ensure it is seated to the correct depth so it accurately reads the core temperature.

6. 6

   Reconnect

   Plug the electrical connector back in, ensuring it clicks and locks securely.

7. 7

   Reassembly

   Reinstall the cab roof or trim panels.

8. 8

   Clear Codes and Test

   Reconnect the battery. Turn the ignition on and use a diagnostic tool to clear the 10.03.10 fault code. Start the tractor, turn the A/C to its coldest setting, and verify that the compressor engages and cycles properly without the evaporator freezing over.