Case IH 520601-05 - BCM – BCM: Work lamp #4 - open circuit

The control module has detected an incomplete electrical path in the circuit responsible for powering Work Lamp #4. This is typically caused by a burnt-out bulb, a disconnected plug, a broken wire, or a blown fuse/circuit breaker.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect

1. 1

   Turn on the work lamps and visually verify if Work Lamp #4 is illuminating.

2. 2

   Disconnect the harness at Work Lamp #4, turn the ignition and work lamp switch ON, and use a voltmeter to check for 12 volts at the connector (12V indicates a lamp issue, 0V indicates a wiring/fuse issue).

3. 3

   With the battery disconnected, use a multimeter to check for continuity along the wiring harness between the BCM output pin for Work Lamp #4 and the lamp connector.

4. 4

   Check the load side of the circuit breaker or fuse panel for the work lamps to ensure power is being supplied to the circuit.

1. 1

   Power Down

   Turn off the ignition and disconnect the negative battery cable (or turn off the battery isolator switch) to prevent sparks or electrical damage.

2. 2

   Inspect/Replace the Lamp

   If the diagnostic voltage check showed power at the connector but the light didn't work, the bulb or LED housing has failed. Replace the Work Lamp #4 bulb or the entire sealed LED assembly.

3. 3

   Repair the Harness

   If the diagnostic checks revealed no voltage at the connector, trace the wiring harness back to the BCM. Locate the break, chafed wire, or corroded connector pin.

4. 4

   Splice/Clean

   Splice and heat-shrink any broken wires. Clean any corroded connector pins with contact cleaner and apply dielectric grease.

5. 5

   Test

   Reconnect the battery, turn the ignition ON, and activate the work lamps. Verify that Work Lamp #4 illuminates and use the diagnostic display to ensure the 520601-05 active fault code has cleared.