Massey Ferguson 10.03.32 – AIRCON: Issue With Signal To Right Cab Fan Speed Controller (AIRCON)

The climate control system is detecting an irregular, missing, or out-of-range electrical signal to the right-side blower motor resistor/speed controller. This typically results in the right cab fan either not blowing at all or only operating on a single speed (usually high).

• 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

   Test Fan Operation: Turn on the HVAC system and test the right cab fan across all speed settings. If it only works on high speed or not at all, the blower resistor has likely failed.

2. 2

   Inspect Electrical Connections: Access the right fan speed controller (resistor) and inspect the wiring harness and plug-in connector. Look for corrosion from humidity, melted plastic, or burnt pins caused by electrical resistance heat.

3. 3

   Check Signal Voltage: Verify that the AIRCON module is sending the correct signal voltage to the controller through the harness.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery before starting any electrical work. Allow the HVAC system to cool down if the fan has been running, as resistors generate significant heat.

2. 2

   Locate the Resistor

   Access the HVAC blower assembly (typically located in the cab roof). Locate the right cab fan speed controller/resistor, which mounts near the blower motor so that airflow can help keep it cool.

3. 3

   Disconnect

   Unplug the electrical connector from the resistor.

4. 4

   Remove

   Remove the mounting screws holding the old resistor in place and extract the unit.

5. 5

   Clean

   Clean the mounting area and ensure there is no debris blocking ventilation around the resistor, which could cause the new unit to overheat.

6. 6

   Install

   Insert the new resistor, secure it with the mounting screws, and plug the electrical connector back in.

7. 7

   Test

   Reconnect the battery, turn on the tractor, and test the right fan on all speed settings to ensure the fault code clears and airflow is restored.