Massey Ferguson 10.03.33 – AIRCON: Air Vent Circulation Flap Position Sensor Voltage Issue (AIRCON)

The signal from the potentiometer inside the recirculation actuator (which controls whether the HVAC system pulls in fresh outside air or recirculates cabin air) is outside its normal operating voltage range. When this fault is triggered, the system will typically default the recirculation actuator to the "external air" (fresh air) position as a failsafe.

• 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
• MF 6700 S
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8600 Series

1. 1

   Inspect the wiring harness leading to the recirculation actuator for any physical damage, chafing, or breaks.

2. 2

   Disconnect the plug at the actuator and use a multimeter to verify that the proper reference voltage is reaching the sensor.

3. 3

   Test the potentiometer reference circuit to ensure it is not short-circuited to the earth (ground) or open.

4. 4

   Manually inspect the physical air circulation flap/door to ensure it is not jammed by debris (like dust or leaves) which could cause the actuator motor to stall and throw an out-of-range voltage code.

1. 1

   Access the HVAC Unit

   Depending on the tractor model, access the main HVAC housing (typically located in the cab roof panel or under the rear cab trim).

2. 2

   Locate the Actuator

   Identify the recirculation actuator (often labeled as actuator No. 1 or No. 2 in the service manual).

3. 3

   Remove the Faulty Actuator

   Disconnect the electrical connector from the actuator. Remove the mounting screws holding the actuator to the HVAC housing and pull it free from the blend door shaft.

4. 4

   Install the New Actuator

   Align the new actuator with the blend door shaft and secure it with the mounting screws. Reconnect the electrical harness.

5. 5

   Clear the Fault Code

   Use the AGCO Electronic Diagnostic Tool (EDT) or the tractor's onboard diagnostic menu to clear the 10.03.33 fault code.

6. 6

   Test Operation

   Turn on the tractor and cycle the HVAC system between "Recirculate" and "Fresh Air" to ensure the flap moves smoothly and no new codes are logged.