Case IH 520560-00 - BCM – BCM: Overcurrent or overload condition on the cab's left wiper motor circuit

The controller has detected that the motor is drawing too much amperage ('too many loads or faulty load'). This is typically caused by a seized motor, mechanical binding in the wiper linkage, a short to ground in the wiring, or a failed relay.

• MAGNUM AFS Connect
• Case IH Puma series
• Case IH Maxxum series
• Case IH Magnum series
• Case IH Axial-Flow Combines

1. 1

   Inspect the left wiper arm and linkage for mechanical binding, debris, or a blade frozen to the glass.

2. 2

   Locate and swap the wiper motor high/low relays in the cab fuse panel to check for fused or failing contacts.

3. 3

   Disconnect the electrical connector at the left wiper motor and activate the wiper switch to see if the fault changes to an 'open circuit' code (indicating an internally shorted motor).

4. 4

   If the overcurrent code persists with the motor unplugged, use a multimeter to check for a short-to-ground on the power supply wire between the BCM/relay panel and the motor connector.

1. 1

   Disconnect Power

   Turn off the battery disconnect switch to prevent accidental short circuits while working on the BCM harness.

2. 2

   Remove Wiper Arm

   Unbolt and remove the exterior wiper arm from the motor's splined pivot shaft.

3. 3

   Access the Motor

   Remove the cab ceiling trim / headliner to access the internal framework where the wiper motor is mounted.

4. 4

   Disconnect Harness

   Unplug the electrical connector from the faulty wiper motor.

5. 5

   Remove Motor

   Remove the retaining nuts securing the motor unit to the cab frame and withdraw the motor.

6. 6

   Install New Motor

   Insert the new wiper motor through the cab frame and secure it with the mounting nuts. Caution: Always use appropriate tools to align fixing holes; never use fingers to align linkages.

7. 7

   Reassembly

   Reconnect the electrical harness, reinstall the cab ceiling trim, and reattach the exterior wiper blade.

8. 8

   Calibration/Testing

   Turn on the battery power, clear the BCM fault codes using a diagnostic tool, and test the wiper switch to ensure proper park position and operation.