Case IH 518864-06 - BCM – BCM: ATC right vent door actuator - over voltage / current above normal

The system flags a grounded circuit, a short, or an over-voltage condition causing the actuator motor to draw excessive current, which often leads to an over-temperature state.

• MAGNUM AFS Connect

1. 1

   Check the wiring harness between the BCM and the right vent door actuator for a short to ground or an over-voltage condition.

2. 2

   Access the HVAC box and manually check the right vent door to see if it is jammed or binding.

3. 3

   Inspect the multi-pin electrical connector at the actuator for melted plastic, corrosion, or pushed-out pins.

1. 1

   Access the HVAC Unit

   Remove the necessary interior trim panels (often the top cover of the HVAC box located under the seat or within the headliner/dash assembly) to access the vent door actuators.

2. 2

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent further BCM faults.

3. 3

   Remove the Actuator

   Locate the right vent door actuator (a small stepper motor). Disconnect the electrical connector from the actuator and remove the retaining fasteners (typically two hex screws or capscrews) securing the actuator to the HVAC top cover/housing.

4. 4

   Verify Door Movement

   With the actuator removed, manually pivot the vent door to ensure it moves freely without obstruction.

5. 5

   Install the New Actuator

   Position the new actuator over the vent door shaft. Make sure the nylon bushing and washers are correctly positioned inside the heater/air conditioner assembly so the shaft aligns properly with the actuator. Secure the actuator with the retaining screws.

6. 6

   Reassembly & Calibration

   Reconnect the electrical connector, reinstall the HVAC covers, and reconnect the battery. Turn the key on and allow the BCM to initialize; the ATC system may require a key-cycle calibration to learn the new actuator's end-stops.