Massey Ferguson 10.02.29 – Air Conditioning Module (AIRCON): Issue With Voltage To Air Conditioning Module (AIRCON)

Failure due to overvoltage. The electrical supply signal reaching the module is higher than the maximum allowable value, which causes the control unit to automatically deactivate itself to prevent damage.

• 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
• 7714S
• 7719S
• 8650
• 8660
• 8670
• 8680
• 8690

1. 1

   Check baseline battery voltage using a multimeter (a fully charged 12V battery should read around 12.6V).

2. 2

   Test alternator output voltage while the engine is running to check for an overcharging condition (look for related codes like D121 or D125).

3. 3

   Verify the exact supply voltage reaching the Air Conditioning Module and the compressor coil using a multimeter.

4. 4

   Inspect the wiring harness leading to the AIRCON module (specifically blue and yellow connectors on 8600 models) for any shorts to a higher voltage source.

1. 1

   Resolve Charging System Issues

   If your multimeter shows the alternator is outputting excessive voltage (spiking well above 14V), replace the alternator or the alternator voltage regulator.

2. 2

   Repair Wiring Shorts

   If the alternator is functioning normally but the module connector shows overvoltage, trace the wiring harness back to the power distribution panel and repair any shorts to power.

3. 3

   Replace the AIRCON Module

   If the supply voltage at the connector is within normal limits but the module still registers an overvoltage fault and deactivates, the internal circuitry of the Air Conditioning Module has failed. Replace the module.

4. 4

   Clear Codes

   Once the repair is complete, use the diagnostic interface to clear the 10.02.29 fault code and test the air conditioning system to ensure the module remains active.