Massey Ferguson 7 – AIRCON: Air Conditioning Outside Temperature Sensor Open Circuit

The control module is detecting infinite resistance or a complete lack of electrical continuity in the sensor's circuit. This is typically caused by a severed wire, an unplugged connector, severely corroded pins, or a completely failed internal thermistor inside the sensor itself.

• 7724S
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 7619
• 7626
• 7624
• 7726S
• 7614
• 7718S
• 7620
• 7719
• 7714
• 7716S
• 7622
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608–5613
• 5709M–5711M
• 5709S–5713S
• 5710SL–5713SL
• 6712S–6718S
• 6711R–6713R
• 7614–7626
• 7714–7726S
• 8727S–8740S

1. 1

   Visual Inspection: Locate the outside temperature sensor (usually mounted near the front grille or cab air intake). Inspect the sensor's electrical connector for loose pins, dirt, or green corrosion.

2. 2

   Wiring Harness Check: Trace the pigtail wiring back from the sensor to the main harness. Look for chafing, rodent damage, or pinched wires that could sever the connection.

3. 3

   Multimeter Resistance Test: Unplug the sensor and measure the resistance across its pins with a multimeter. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally and must be replaced.

4. 4

   Continuity Test: If the sensor tests fine, check the continuity of the wiring harness between the sensor plug and the AIRCON module to rule out a broken wire in the tractor's harness.

1. 1

   Power Down

   Turn off the tractor ignition and remove the key to ensure the AIRCON module is powered down.

2. 2

   Disconnect

   Locate the outside temperature sensor and carefully depress the locking tab on the electrical connector to unplug it.

3. 3

   Remove

   Unbolt or unclip the faulty sensor from its mounting bracket.

4. 4

   Install

   Mount the new replacement sensor into the factory location and secure it.

5. 5

   Reconnect

   Plug the electrical harness into the new sensor. Ensure the weather-pack seal is intact and the connector clicks firmly into place.

6. 6

   Clear Codes

   Turn the tractor on. The AIRCON module may clear the code automatically once it detects the proper resistance value. If not, use a diagnostic scan tool to clear the stored 10.00.07 / Code 7 fault.