Case IH 520594-05 - BCM – BCM: License Plate Lights Open Circuit

The fault code 520594-05 indicates a 'License plate lights - open circuit'. The Body Control Module (BCM) has detected a break in the electrical path to the license plate lamp. This is most commonly caused by a blown bulb filament, a severed wire, a disconnected harness plug, or a heavily corroded ground connection.

• MAGNUM AFS Connect
• JX60
• JX70
• JX75
• JX80
• JX90
• JX95
• JX100
• JX110
• Farmall 75A
• Farmall 85A
• Farmall 95A
• Farmall 105A
• Farmall 115A
• Farmall 85C
• Farmall 105C
• Farmall 105U
• Farmall 110U
• Farmall 115U
• Maxxum 110
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Maxxum 145
• Puma 130
• Puma 145
• Puma 150
• Puma 160
• Puma 165
• Puma 170
• Puma 180
• Puma 185
• Puma 195
• Puma 200
• Puma 210
• Puma 215
• Puma 220
• Puma 225
• Puma 230
• Puma 240
• Magnum 180
• Magnum 200
• Magnum 210
• Magnum 220
• Magnum 240
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Axial-Flow 5130
• Axial-Flow 6130
• Axial-Flow 7130
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230

1. 1

   Visual Bulb Inspection: Check the license plate light bulb to see if the filament is broken or burnt out. A blown bulb is the most common cause of an open circuit code.

2. 2

   Moisture/Corrosion Check: Open the lamp housing and inspect the socket contacts for water damage, rust, or green copper corrosion.

3. 3

   Ground Connection Check: Inspect the ground plate and ground wire for the lamp assembly. A loose or corroded ground will break the circuit.

4. 4

   Wiring Harness Inspection: Trace the wiring harness from the license plate lamp back toward the BCM. Look for intermittent wiring harness shorts, chafed wires, or disconnected plugs.

1. 1

   Disconnect Power

   Turn off the machine's ignition and disconnect the battery to prevent accidental short circuits while working on the BCM wiring.

2. 2

   Access the Lamp

   Locate the license plate lamp assembly (often mounted on the rear mudguard or cab roof). Remove the retaining screws (commonly M3.5 x 13 self-tapping screws) to release the lens or housing.

3. 3

   Replace the Bulb

   If the bulb is blown, remove it and install a new 12V C5W or W5W bulb.

4. 4

   Clean Contacts

   If the bulb is intact but the light doesn't work, clean the socket connections with a wire brush. Apply a small amount of dielectric grease to the contacts to prevent future water ingress and corrosion.

5. 5

   Repair Wiring

   If the socket is clean and the bulb is good, use a multimeter to test for continuity along the license plate wire harness (e.g., harness part 82035389). Repair any severed wires or replace the harness section if heavily damaged.

6. 6

   Reassemble and Test

   Reinstall the lamp housing, reconnect the battery, and turn on the exterior lights. Verify that the license plate light illuminates and that the BCM fault code 520594-05 clears.