Case IH 520570-00 - BCM – BCM: BCM: Rear wiper motor - too many loads or faulty load

The BCM has detected an excessive current draw (amperage spike) or an irregular electrical load on the circuit supplying the rear wiper motor, typically caused by mechanical binding, physical obstruction, a short-to-ground, or internal motor failure.

• MAGNUM AFS Connect
• Farmall C
• Farmall JX
• Farmall A
• Maxxum 51
• Maxxum 52
• Maxxum MX
• MX Magnum (MX180 - MX270)
• Puma Series
• Steiger Series

1. 1

   Check the rear wiper blade and arm for physical obstructions (ice, mud, or debris) that could cause the motor to bind and draw excessive current

2. 2

   Disconnect the wiper arm and manually test the pivot shaft for corrosion or seizing

3. 3

   Disconnect the rear wiper motor harness and use a multimeter to check the power and ground supply at the connector while the wiper switch is activated

4. 4

   Inspect the wiring harness running from the BCM to the rear roof/window area for chafing, pinched wires, or exposed copper that could cause a short-to-ground

5. 5

   Apply a fused 12V jumper wire directly to the wiper motor terminals to test for internal shorts (if the motor fails to move or blows the fuse, it must be replaced)

1. 1

   Disconnect Power

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical shorts or accidental BCM damage.

2. 2

   Remove the Wiper Arm

   Lift the plastic cap at the base of the exterior rear wiper arm, remove the retaining nut, and carefully pull the wiper arm off the splined motor shaft.

3. 3

   Access the Motor

   Inside the cab, remove the rear plastic trim panels or the rear section of the headliner to expose the wiper motor assembly.

4. 4

   Disconnect Wiring

   Unplug the electrical harness connector from the wiper motor.

5. 5

   Remove the Motor

   Support the motor assembly and remove the mounting bolts securing the bracket to the cab frame or rear glass. Carefully extract the faulty motor.

6. 6

   Install the New Motor

   Position the new wiper motor assembly, aligning the shaft through the rear window/cab opening, and secure the mounting bolts.

7. 7

   Reconnect Systems

   Plug the electrical harness back into the new motor and reinstall the interior cab trim panels.

8. 8

   Reattach the Wiper Arm

   Place the exterior wiper arm back onto the splined shaft in the correct "parked" position, install the retaining nut, and snap the plastic cover back into place.

9. 9

   Test

   Reconnect the battery, turn on the ignition, and test the rear wiper to ensure smooth operation and verify that the BCM fault code has cleared.