Case IH 518109-05 - BCM – BCM: Work lamp #12 - open circuit

The controller is sending a command to turn on Work Lamp #12, but it detects zero or abnormally low current draw. This is typically caused by a burnt-out bulb, a disconnected plug, a severed power wire, or a broken ground connection.

• MAGNUM AFS Connect
• Magnum series
• Steiger series
• Puma series
• Axial-Flow combines

1. 1

   Check the bulb for a broken filament or internal failure, as a burnt-out bulb is the most common cause.

2. 2

   Inspect the electrical connector at Work Lamp #12 for loose connections, bent pins, pushed-out terminals, or moisture/mud contamination.

3. 3

   Test for voltage and ground at the lamp connector. With the key ON and switch activated, you should see 12 volts. Check the ground pin for continuity to the chassis.

4. 4

   Check the harness for continuity. If there is no voltage at the lamp, disconnect the corresponding connector at the BCM and test the signal wire for an open circuit between the BCM and the lamp.

1. 1

   Power Down

   Turn off the ignition switch and disconnect the negative battery cable to prevent accidental short circuits during repair.

2. 2

   Access the Lamp

   Locate Work Lamp #12 on the machine. Remove the lens or housing to access the bulb/LED element.

3. 3

   Replace the Bulb (If Applicable)

   If the filament is broken or the LED is internally failed, replace the work lamp bulb or sealed assembly.

4. 4

   Repair Wiring (If Bulb is Good)

   If the bulb tests fine, trace the wiring harness back from the lamp toward the BCM. Locate the break or chafed wire causing the open circuit.

5. 5

   Splice the Wire

   Repair any broken wires using environmental splices (solder and heat-shrink tubing) to prevent future moisture intrusion.

6. 6

   Clean Contacts

   If the connector is heavily oxidized, clean the pins with electrical contact cleaner and apply dielectric grease before reconnecting.

7. 7

   Clear the Code

   Reconnect the battery. Turn the key ON and activate the work lamp switch. If the lamp illuminates, the active fault will transition to an inactive/stored state. Use the Case IH Electronic Service Tool (EST) or the Advanced Information Center (AIC) display to clear the stored fault code.