Massey Ferguson 10.00.28 – Air Conditioning Module (AIRCON): Issue With Voltage To Air Conditioning Module (AIRCON)

The electronic control system has detected an improper voltage supply (either too high, too low, or an open/short circuit) reaching the cab's automatic or manual air conditioning control module. Without the correct voltage, the module cannot properly regulate the HVAC system, blower fans, or compressor clutch engagement.

• 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
• 8650
• 8660
• 8670
• 8680
• 8690

1. 1

   Check battery and alternator voltage: Verify the battery is resting at ~12.6V. Start the tractor and check the alternator output for voltage spikes or drops.

2. 2

   Inspect fuses and relays: Check the cab fuse panel for blown HVAC fuses (e.g., F52 or F53). Test the A/C relays, including fan speed relays X429-X432 and the main A/C relay.

3. 3

   Inspect wiring harness and connectors: Locate the Air Conditioning Control Module and inspect the main electrical connectors (blue X439 and yellow X440) for corrosion, loose pins, or moisture.

4. 4

   Check compressor coil voltage: Verify proper voltage is reaching the A/C compressor clutch coil. A short here can pull down circuit voltage.

1. 1

   Disconnect Power

   Always disconnect the negative battery terminal before working on the tractor's electrical system to prevent short circuits.

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks revealed chafed wiring or corroded connector pins at the AIRCON module, repair the wiring harness using OEM-approved splice kits or clean the pins with electrical contact cleaner.

3. 3

   Replace Faulty Relays/Fuses

   Replace any blown fuses. If the A/C clutch supply voltage is dropping, install a low voltage clutch coil protection relay kit if applicable to your specific model.

4. 4

   Module Replacement

   If deemed faulty: Remove the interior cab trim panels required to access the HVAC/AIRCON module. Carefully unplug the wiring harnesses (e.g., blue and yellow connectors). Remove the mounting screws securing the module to the HVAC housing. Install the new Air Conditioning Module and secure it. Reconnect the wiring harnesses, ensuring they click firmly into place. Reinstall the cab trim panels.

5. 5

   System Reset

   Reconnect the battery. Turn the ignition on and use the Dash Control Center or a diagnostic scan tool to clear the inactive 10.00.28 fault code. Test the A/C system through all fan speeds and temperature ranges to ensure the voltage issue is resolved.