Case IH 520583-05 - BCM – BCM: Reverse lights - open circuit

The control module is attempting to send power to the reverse lights but is not detecting a complete electrical path (continuity). This is typically caused by a blown bulb, a disconnected plug, a broken wire in the harness, or a failed reverse light switch/relay.

• MAGNUM AFS Connect
• Steiger
• Optum

1. 1

   Check the rear reverse light bulbs or LED assemblies to see if they are burnt out or physically damaged

2. 2

   Inspect the electrical connectors at the rear tail/reverse light assemblies to ensure they are securely plugged in and free of corrosion or moisture

3. 3

   Check for continuity along the wiring harness from the reverse light connectors back toward the BCM using a multimeter, looking for pinched, chafed, or broken wires

4. 4

   Verify that the ground wire for the reverse light circuit is securely fastened to the chassis and free of rust

5. 5

   Test the reverse light switch and the associated lighting relays in the fuse/relay box to ensure they are closing the circuit properly when shifted into reverse

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Lights

   Locate the reverse light assemblies at the rear of the tractor (often integrated into the LH/RH tail light housings).

3. 3

   Inspect/Replace the Bulb

   Disconnect the wiring pigtail and remove the bulb or LED unit. If the filament is broken or the LED is dead, replace it with a new bulb/assembly.

4. 4

   Repair Wiring (If Applicable)

   If the bulb is good, trace the wiring harness back from the light. If a break or severe corrosion is found, cut out the damaged section and splice in a new wire using weather-sealed heat-shrink butt connectors.

5. 5

   Check the Relay

   If the wiring and bulbs are intact, locate the reverse light/indicator relay in the fuse panel. Swap it with a known good relay of the same type to see if functionality returns. Replace if faulty.

6. 6

   Reassemble and Test

   Reconnect the battery. Turn the key to the ON position (engine off) and shift the tractor into reverse. Verify that the reverse lights illuminate.

7. 7

   Clear Codes

   Use the AFS Pro display or a diagnostic service tool to clear the inactive 520583-05 fault code from the BCM memory.