Case IH 518864-12 - BCM – BCM: ATC right vent door actuator - permanent electrical defect

The Automatic Temperature Control (ATC) system has detected a hard electrical failure in the actuator responsible for moving the right-side HVAC vent/blend door. This is typically caused by an internal short, an open circuit within the actuator's motor/potentiometer, or a severed wiring harness connection.

• MAGNUM AFS Connect
• Magnum AFS Connect 250
• Magnum AFS Connect 280
• Magnum AFS Connect 310
• Magnum AFS Connect 340
• Magnum AFS Connect 380
• Magnum AFS Connect 400
• Steiger AFS Connect

1. 1

   Check for related right vent door codes from the BCM, such as 518864-03 (over-voltage) or 518864-06 (over-temperature/short to ground)

2. 2

   Inspect the 6-pin electrical connector at the actuator for pushed-out pins, corrosion, or chafed wires leading back to the BCM

3. 3

   Ensure the right vent door linkage is not physically jammed by debris inside the HVAC box, which can cause the actuator motor to burn out

1. 1

   Access the HVAC Box

   The HVAC unit is located under the seat and armrest assembly. Disassemble the armrest from the bottom and remove the entire seat assembly out the back window of the cab (sometimes utilizing a pallet on a forklift) to fully access the HVAC system.

2. 2

   Remove the Actuator

   Once the HVAC box is exposed, locate the right vent door actuator and disconnect the 6-pin wiring harness.

3. 3

   Dismount

   Remove the mounting screws securing the actuator to the HVAC housing and pull the actuator off the blend door shaft.

4. 4

   Install the New Part

   Align the splines of the new actuator with the vent door linkage. Secure it with the mounting screws and reconnect the electrical harness.

5. 5

   Reassembly & Calibration

   Reinstall the seat and armrest assembly. Reconnect the battery. Use the Case IH Electronic Service Tool (EST) to clear the BCM fault codes and run an ATC calibration so the BCM can learn the end-stops of the new actuator.