Case IH 519667-06 - BCM – BCM: ATC rear vent door actuator - over temperature

The actuator controlling the rear vent door for the Automatic Temperature Control (ATC) system is drawing excessive current or has overheated. This is typically caused by a mechanical bind in the vent door, a short circuit in the wiring, or an internal failure of the actuator motor itself.

• MAGNUM AFS Connect

1. 1

   Check for mechanical binding: Manually inspect the rear vent door mechanism to ensure it is not physically jammed, obstructed by debris, or binding on its hinges.

2. 2

   Inspect the wiring harness: Check the wiring harness running between the BCM and the ATC rear vent door actuator for chafed wires, pinched harnesses, or shorts to ground/power.

3. 3

   Inspect connectors: Disconnect the actuator and inspect the electrical connector pins for melting, corrosion, or pushed-out pins.

4. 4

   Test actuator resistance: Use a multimeter to test the internal resistance of the actuator motor to see if it has shorted internally.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery ground cable to prevent electrical spikes.

2. 2

   Access the HVAC Unit

   Remove the necessary interior cab trim panels (typically in the cab roof/headliner or rear cab panel, depending on the specific cab configuration) to access the ATC HVAC distribution box.

3. 3

   Locate the Actuator

   Identify the specific actuator controlling the rear vent door.

4. 4

   Remove the Actuator

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

5. 5

   Verify Door Movement

   With the actuator removed, manually rotate the blend door shaft by hand. It should move freely from stop to stop. If it binds, the HVAC housing or door must be repaired or replaced.

6. 6

   Install the New Actuator

   Align the new actuator with the door shaft and secure it with the mounting screws. Do not overtighten, as the plastic housing can crack.

7. 7

   Reconnect and Reassemble

   Plug the electrical connector back into the actuator and reinstall all cab trim panels.

8. 8

   Clear Codes and Calibrate

   Reconnect the battery. Turn the key to the ON position and use a diagnostic tool (or the AFS Pro display) to clear the BCM fault codes. Cycle the ATC system through its temperature and vent settings to verify proper operation and allow the system to calibrate the new actuator's end-stops.