Case IH 518862-06 - BCM – BCM: ATC recirculation box / blend door actuator - over temperature

The actuator motor controlling the Automatic Temperature Control (ATC) recirculation or blend door has exceeded its normal operating temperature threshold, likely due to electrical resistance, a short, or physical binding.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect Tier 3

1. 1

   Perform a thorough visual inspection of the HVAC wiring harness to ensure there are no disconnected wires or obvious electrical faults.

2. 2

   Check the inlet and outlet temperatures of the heater core to confirm they are hot and coolant is flowing properly.

3. 3

   Change the temperature/recirculation settings on the ATC display and observe if the blend door actuator operates at all.

4. 4

   Remove the actuator from the housing and manually move the blend door. Ensure the door operates smoothly without binding, as a physically stuck door will cause the actuator motor to overwork and overheat.

5. 5

   Check for proper power and ground at the blend door actuator connector. If both are present but the actuator does not move or overheats, the actuator itself is at fault.

1. 1

   Access HVAC box

   Gain access to the HVAC box by removing the glove box or interior cab access panels.

2. 2

   Locate actuator

   Locate the over-temperature ATC blend door/recirculation actuator.

3. 3

   Disconnect harness

   Disconnect the electrical wiring harness from the actuator.

4. 4

   Remove actuator

   Remove the retaining screws holding the actuator in place, and detach the actuator rod assembly to remove the unit.

5. 5

   Install new actuator

   Install the new blend door actuator and secure it with the retaining screws.

6. 6

   Reconnect harness

   Reconnect the electrical harness to the new actuator.

7. 7

   Perform calibration

   Perform an electronic relearn/calibration procedure so the BCM can learn the new actuator's limits and confirm proper operation of the climate control system.

8. 8

   Reassemble cab panels

   Reinstall the glove box and any removed cab panels.