John Deere 876.04 – ATC (Automatic Temperature Control / ClimaTrak System): Compressor Clutch Circuit Voltage Low / Air-Conditioning Relay, Grounded Circuit / Compressor Clutch On, Current Too High

The ClimaTrak controller has detected a short to ground or an excessive current draw on the circuit that supplies power to the A/C compressor clutch relay (K09/4) or the compressor clutch itself (M02). The ATC module will restrict temperature control and prevent the compressor clutch from engaging to protect the circuit.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6020 to 6920S
• 6120 to 6420
• 6120L to 6520L
• 6230
• 6330
• 6430
• 7715
• 7815
• 7720
• 7820
• 7920
• 8310RT
• 8335RT
• 8360RT
• 9430
• 9530
• 9630
• 9470RT
• 9520RT
• 9570RT

1. 1

   Restart the engine to verify if the active Service Code reappears, as communication messages can sometimes trigger a false code that clears upon a restart

2. 2

   Perform a circuit/harness test for the Air-Conditioning Relay (K09/4) and check for continuity to ground on the control wire

3. 3

   Disconnect the A/C compressor clutch (M02) electrical connector to isolate the component; if the short/high-current condition disappears, the clutch coil is internally shorted

4. 4

   Visually inspect the wiring harness between the ATC module, the K09/4 relay, the thermostat switch (B14), the pressure switch (B15), and the compressor clutch (M02) for chafing, melted insulation, or pinched wires

1. 1

   Access the Relay Panel

   Locate the electrical relay center (often K10 relay box on 6000/7000 series) and identify the A/C compressor clutch relay (K09/4).

2. 2

   Test/Replace the Relay

   Swap the K09/4 relay with a known good relay of the same type. If the A/C clutch engages and the code clears, replace the relay permanently.

3. 3

   Test the Compressor Clutch Coil

   If the relay is good, use a multimeter to measure the resistance of the A/C compressor clutch coil. If the resistance is near zero (shorted), the clutch assembly is drawing too much current and must be replaced.

4. 4

   Repair Wiring

   If both the relay and clutch coil test good, trace the wiring harness along the engine block and chassis. Repair any sections where the wire insulation has rubbed through and is grounding out against the tractor frame.

5. 5

   Clear Codes

   Reconnect all components, turn the key on, and clear the ATC codes via the CommandCenter display. Run the A/C system to verify the repair.