Case IH 4057-00 - BCM – BCM: Front wiper low speed motor - too many loads or faulty load

The fault description indicates an overcurrent, short circuit, or high-resistance condition on the low-speed circuit of the front windshield wiper motor.

• MAGNUM AFS Connect
• Magnum
• Steiger
• Optum
• Puma

1. 1

   Visual & Mechanical Inspection: Ensure the front wiper blades are not frozen to the glass, obstructed by debris, or physically jammed. Disconnect the wiper linkage from the motor and verify the linkage moves freely by hand.

2. 2

   Check Fuses and Relays: Inspect the cab fuse panel for a blown front wiper fuse or a sticking wiper relay.

3. 3

   Motor Amperage Draw Test: Disconnect the wiper motor connector. Provide fused, direct 12V power and ground to the low-speed pin on the motor. Use a multimeter to measure the amperage draw. If the motor draws excessive amperage or fails to spin, the motor is internally faulty.

4. 4

   Harness Integrity Check: With the motor disconnected, use a multimeter to check the low-speed power wire from the BCM to the motor for continuity, short-to-ground, or short-to-power.

5. 5

   Connector Inspection: Check the BCM and wiper motor connectors for water intrusion, pushed-out pins, or green corrosion.

1. 1

   Turn off the machine's battery disconnect switch to prevent accidental BCM damage.

2. 2

   Remove the cab interior trim panels or exterior cowl panels required to access the front wiper motor assembly.

3. 3

   Mark the resting position of the wiper arm on the windshield, then unbolt and remove the wiper arm.

4. 4

   Disconnect the electrical harness connector from the wiper motor.

5. 5

   Unbolt the wiper motor from its mounting bracket and detach it from the mechanical linkage.

6. 6

   Install the new wiper motor to the linkage and secure it to the mounting bracket.

7. 7

   Reconnect the electrical harness.

8. 8

   Turn on the battery disconnect, power on the machine, and cycle the wipers to ensure the motor parks in the correct position before reinstalling the wiper arm.

9. 9

   Reinstall the wiper arm at the marked resting position.

10. 10

    Clear the 4057-00 fault code from the BCM using a diagnostic tool (like CNH EST) and verify the wipers operate correctly on low speed.