Case IH 2636-06 - BCM – BCM: Short circuit to ground on the front wiper high-speed motor circuit

The voltage intended for the high-speed winding of the front windshield wiper motor is finding an unintended path to the vehicle's chassis ground before reaching the motor, or the relay/wiring itself is shorted to ground. When the controller detects this excessive current draw or lack of resistance, it disables the circuit to prevent electrical fire or module damage and logs the 06 (short to ground) failure mode.

• MAGNUM AFS Connect
• Maxxum
• Puma
• Magnum
• Steiger
• Farmall
• Wheel Loaders

1. 1

   Switch OFF the power supply (ignition key in the OFF position) before disconnecting any electrical connectors to prevent voltage spikes to the BCM.

2. 2

   Check the front wiper output harness for obvious signs of chafing, pinched wires, or melted insulation where the harness routes near the cab frame.

3. 3

   Use a multimeter to perform a continuity test between the wiper motor high-speed signal wire and a known good chassis ground.

4. 4

   Inspect the Front Wiper High Speed Relay for an internal short circuit to ground at the high side power stage.

1. 1

   Turn off the ignition and disconnect the battery negative terminal.

2. 2

   Locate the cab electrical fuse/relay panel and remove the Front Wiper High Speed Relay.

3. 3

   Disconnect the electrical connector directly at the front wiper motor.

4. 4

   Using a digital multimeter set to Ohms (resistance), probe the high-speed output wire at the relay socket and the other multimeter lead to a clean chassis ground.

5. 5

   If continuity to ground is present: The short is in the wiring harness between the relay and the motor.

   Trace the harness, locate the shorted wire, and repair or replace the harness section.

6. 6

   If the wiring tests good (no continuity to ground): The fault lies in either the relay or the motor.

   Test the relay for internal shorts. If defective, replace the Front Wiper High Speed Relay.

7. 7

   If the relay and wiring are both good, the internal high-speed windings of the wiper motor are shorted to the motor casing.

   Replace the front wiper motor assembly.

8. 8

   Reconnect all components, restore battery power, clear the BCM fault codes, and test the wiper system on all speed settings to verify the repair.