John Deere 1550.06 – ECU, VLC, CCU, or EMU: A/C Compressor Clutch Circuit Current High

The control unit has detected that the electrical current in the air conditioning compressor clutch circuit exceeds the maximum fuse rating (typically 7 amps). This condition indicates a potential short circuit to ground or an excessive electrical load within the circuit, which causes the system to prevent the A/C compressor from engaging to avoid further damage.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5085M-5115ML series
• 8130-8530 series
• 9230-9630 series
• 318D
• 320D
• 325
• 328
• 250D Series II
• 300D Series II
• 944K Hybrid 4WD Loaders
• Machines utilizing the 3029 Diesel Engine

1. 1

   Inspect Wiring and Connections: Examine the wiring harness and connectors in the A/C compressor clutch circuit (often designated as component Y22 or Y16) for signs of short circuits, such as damaged insulation, chafing, or exposed wires.

2. 2

   Test the Relay and Fuse: Verify that the relay (e.g., K7) and fuse for the A/C compressor clutch circuit are correctly rated and not malfunctioning. Check for continuity between the control unit pins and the relay.

3. 3

   Measure Circuit Current: Use a multimeter to measure the current draw in the A/C compressor clutch circuit to confirm it is actually exceeding the 7-amp threshold.

4. 4

   Check the A/C Compressor Clutch: Ensure the clutch itself is not drawing excessive current due to an internal coil short or a mechanical fault binding the clutch.

1. 1

   Resolve Wiring Issues

   If the diagnostic checks reveal chafed wires or a short to ground in the harness (e.g., Front Frame Harness W2 or Cab Harness), repair or replace the affected wiring and connectors.

2. 2

   Replace Fuses/Relays

   Replace any blown fuses or faulty relays with components of the exact OEM rating.

3. 3

   Replace the Compressor Clutch

   If the wiring is intact but the clutch coil is internally shorted (drawing excessive amperage), remove and replace the A/C compressor clutch assembly.

4. 4

   Clear Codes and Reprogram

   Clear the fault codes from the monitor. On certain heavy construction models (like the Articulated Dump Trucks), you may need to program the Chassis Control Unit (CCU) after resolving the circuit fault.