John Deere 876.03 – ATC (Air Conditioning Module): Compressor Clutch Circuit Voltage High

The control module has detected an abnormally high voltage on the A/C compressor clutch circuit. This is typically caused by a short circuit to a power source in the wiring harness, a failed A/C compressor clutch relay, or an open circuit/high resistance that disrupts the module's voltage drop monitoring. The system will usually disable the A/C compressor to prevent damage, resulting in a lack of cabin cooling.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6020-6920 series
• 7715
• 7815
• 7720
• 7820
• 7920
• 8225R
• 8245R
• 8320R
• 8400R
• 9330
• 9430
• 9530
• 9630
• 770G
• 770GP
• 772G
• 772GP
• CH570
• CH670

1. 1

   Locate the A/C compressor clutch relay in the fuse panel and swap it with a known good relay (e.g., horn relay) to see if the fault changes or clears.

2. 2

   Inspect the wiring harness running from the ATC module to the relay, and from the relay to the A/C compressor clutch for chafed wires shorting to a 12V power source or broken wires.

3. 3

   Disconnect the pigtail connector at the A/C compressor clutch and inspect for corrosion, moisture, or pushed-out pins.

4. 4

   Use a multimeter to measure the voltage at the compressor clutch connector when the A/C is commanded ON.

5. 5

   Check the resistance of the A/C compressor clutch coil to ensure it is not completely open (infinite resistance) or internally shorted.

1. 1

   Disconnect battery

   Turn off the machine, remove the key, and disconnect the negative battery cable to ensure safety.

2. 2

   Replace A/C compressor clutch relay

   If diagnostics point to the relay, remove the faulty A/C compressor clutch relay from the fuse block and install a new OEM replacement.

3. 3

   Repair or replace wiring harness

   If the wiring harness is damaged (shorted to power or broken), splice and repair the affected section of the wire using weather-sealed heat-shrink connectors, or replace the affected harness section.

4. 4

   Replace A/C compressor clutch assembly

   If the compressor clutch coil failed the resistance test, remove the serpentine belt from the A/C compressor. Remove the center bolt holding the clutch plate, remove the snap rings, and slide the old pulley and clutch coil off the compressor shaft. Install the new A/C compressor clutch assembly and re-install the belt.

5. 5

   Reconnect battery

   Reconnect the negative battery cable.

6. 6

   Clear fault code

   Turn the key ON and use the CommandCenter display (or a John Deere Service ADVISOR tool) to acknowledge and clear the ATC 000876.03 code.

7. 7

   Verify repair

   Start the engine and engage the air conditioning to verify that the compressor clutch cycles properly and the code does not return.