Case IH 2636-05 - BCM – BCM: Current Below Normal or Open Circuit

The control module is sending a command to activate the wiper motor (or its corresponding relay), but it is not detecting the expected electrical current return. This indicates an open circuit in the front windshield wiper high-speed motor circuit, typically caused by a severed wire, a disconnected or corroded harness connector, a blown fuse, a failed relay, or an internal break within the wiper motor's windings.

• MAGNUM AFS Connect
• Maxxum
• Puma
• Magnum
• Steiger
• Optum
• Axial-Flow 7010
• Axial-Flow 8010
• Axial-Flow 2388
• Axial-Flow 2588

1. 1

   Check the cab fuse panel for a blown wiper motor fuse and test the Wiper High/Low and Wiper On/Off relays by swapping them with known good relays.

2. 2

   Visually inspect the wiring harness between the BCM, wiper switch, and wiper motor for chafed wires, pinched harnesses, or disconnected plugs (especially at cab roof connectors).

3. 3

   Verify the BCM is receiving the correct voltage signal from the multifunction wiper switch when set to the high-speed position.

4. 4

   Disconnect the wiper motor connector, turn ignition ON, set wiper switch to high speed, and measure for 12V power at the harness connector and ground continuity to the cab frame.

5. 5

   Test the motor for an internal open by measuring resistance (Ohms) across the power and ground pins. An infinite reading (OL) confirms an internal open circuit.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Remove the Wiper Arm

   On the exterior of the cab windshield, lift the plastic cap at the base of the 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 screws securing the upper front headliner or the specific plastic trim panel covering the wiper motor assembly.

4. 4

   Disconnect the Motor

   Unplug the 5-pin electrical connector from the wiper motor.

5. 5

   Remove the Assembly

   Unbolt the mounting bracket screws securing the wiper motor to the cab frame. Carefully withdraw the motor, ensuring the shaft clears the hole in the cab glass/frame.

6. 6

   Install the New Motor

   Guide the new motor's splined shaft through the cab opening and secure the mounting bracket with the original bolts.

7. 7

   Reconnect Wiring

   Plug the electrical connector back into the new motor.

8. 8

   Reassemble

   Reinstall the interior headliner/trim panels.

9. 9

   Reattach the Wiper Arm

   Reinstall the exterior wiper arm in the correct "parked" position and tighten the retaining nut.

10. 10

    Test

    Reconnect the battery, turn the ignition ON, and test the wipers on all speed settings to ensure the fault code is cleared and operation is restored.