Massey Ferguson 10.01.08 – AIRCON: Air Conditioning Outside Temperature Sensor Short Circuit

This fault indicates a Short Circuit in the Outside Temperature Sensor (ambient air temperature sensor) circuit. The electrical signal wire is either touching a ground source, touching another voltage wire, or the sensor itself has failed internally. The controller receives an out-of-bounds voltage signal (usually near 0V), making it impossible to determine the correct outside air temperature, which can prevent the automatic climate control system from cooling properly.

• 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
• 4700 series
• 5700 series
• 6700 series
• 5600 series
• 6100 series
• 6600 series
• 7600 series
• 7700 series
• 8600 series
• 8700 series

1. 1

   Locate the outside temperature sensor (typically mounted near the front grille, cab roof, or fresh air intake) and visually inspect the wiring harness for chafed insulation, pinched wires, or melted spots that could cause a short to ground.

2. 2

   Disconnect the sensor and inspect the electrical connector for moisture, dirt, or bent/corroded pins that could bridge the connection.

3. 3

   Use a multimeter to measure the resistance (Ohms) across the sensor's terminals. If the reading is at or near zero ohms, the sensor is internally shorted.

4. 4

   With the sensor unplugged and the tractor key ON, check the harness side for the proper reference voltage (usually 5V) and ensure the signal wire does not have continuity to the ground wire.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery isolator/negative terminal to prevent electrical spikes during repair.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a short in the wiring harness, cut out the damaged section and splice in new wire using weatherproof heat-shrink connectors.

3. 3

   Replace the Sensor

   If the sensor is internally shorted, unclip or unbolt the faulty sensor from its mounting bracket.

4. 4

   Install New Part

   Snap the new outside temperature sensor into the bracket and plug in the electrical connector, ensuring the weather seal clicks firmly into place.

5. 5

   Reassemble and Clear Codes

   Reconnect the battery. Turn the ignition on and use the AGCO Electronic Diagnostic Tool (EDT) or the tractor's dashboard interface to clear the stored AIRCON fault codes.

6. 6

   Test Operation

   Turn on the AC system and verify that the cab display shows an accurate outside temperature reading and that the AC compressor clutch engages.