Massey Ferguson 10.02.21 – AC Module (AIRCON): Air Conditioning Compressor Relay Signal From AC Module Issue (AIRCON)

This code indicates a communication or electrical failure between the Air Conditioning (AC) control module and the AC compressor relay. The AC module is sending a signal to engage the compressor clutch, but the expected voltage or relay response is not being detected. This typically results in the compressor clutch failing to engage, causing the AC system to blow warm air. If the voltage is too low, the clutch may slip and burn out.

• 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
• 4700
• 5700
• 6700
• 4707
• 4708
• 4709
• 4710
• 5710
• 5711
• 6711
• 6712
• 6713
• 5600
• 7600
• 7700
• 8600
• 7614-7626
• 7714-7726S
• 8650-8690
• 6200
• 6400

1. 1

   Voltage Test at Compressor Coil: Use a multi-meter to check if the proper 12V supply is reaching the compressor coil when the AC is turned on. Without proper voltage, the coil will not have enough power to fully engage the clutch.

2. 2

   Relay Inspection: Locate the AC compressor relay in the main fuse/relay box (often designated as K4 or similar) and swap it with a known good relay of the same type to see if the compressor engages.

3. 3

   Wiring Harness Inspection: If there is no power at the compressor or the relay swap fails, inspect the machine's wiring harness between the AC module, the relay block, and the compressor for any physical damage, chafing, or breaks.

4. 4

   Low Voltage Protection Kit Check: Check if the tractor has a Low Voltage Clutch Coil Protection Kit installed (common on 6200/6400 series and others). A faulty protection relay can trigger signal issues.

1. 1

   Access the Relay Panel

   Turn off the tractor and locate the main electrical fuse/relay box (usually located in the cab console or under the right-hand pillar).

2. 2

   Replace the AC Compressor Relay

   If the relay tested faulty during diagnostics, remove the old relay and install a new OEM 12V relay.

3. 3

   Repair Wiring (If Applicable)

   If a break or short was found in the harness between the AC module and the compressor, splice and heat-shrink the damaged wire, or replace the affected harness section.

4. 4

   Inspect the Compressor Clutch

   If the tractor was operated with low voltage to the clutch for an extended period, the clutch may have slipped and burnt out, potentially ruining the front seal on the pump. If the clutch is burnt, replace the compressor clutch assembly or the entire compressor.

5. 5

   Clear Codes

   Connect the AGCO Electronic Diagnostic Tool (EDT) to the tractor's diagnostic port and clear the 10.02.21 fault code.

6. 6

   System Test

   Start the tractor, turn the AC to maximum cooling, and verify that the compressor clutch engages solidly without slipping and that the cab vents blow cold air.