Case IH 520550-00 - BCM – BCM: BCM: Left extended arm turn indicator - too many loads or faulty load

The Body Control Module (BCM) is detecting an abnormally high electrical current draw on the circuit responsible for the left extended arm turn indicator.

• MAGNUM AFS Connect
• Steiger series
• Magnum series
• Puma series
• Patriot series

1. 1

   Inspect the left extended arm turn indicator housing for physical damage, cracked lenses, or water accumulation.

2. 2

   Verify the bulb or LED module matches OEM wattage specifications, as aftermarket bulbs often draw more current.

3. 3

   Disconnect the left turn indicator and use a multimeter to measure resistance of the power wire to chassis ground to check for a short.

4. 4

   Compare the current draw of the left extended arm indicator to the right extended arm indicator using an amp clamp.

5. 5

   Wiggle the harness at the pivot points while monitoring the multimeter to check for intermittent shorts caused by vibration and folding.

1. 1

   Isolate Power

   Turn off the machine and disconnect the negative battery terminal to prevent further electrical damage.

2. 2

   Address the Component

   If the bulb is the incorrect wattage or the LED module is internally shorted, replace it with the correct OEM component. If the housing is heavily corroded or holds water, replace the entire indicator assembly.

3. 3

   Repair the Harness

   If a short to ground was found in the wiring (commonly at pinch points on the extended arm), cut out the damaged section of wire. Splice in new wire using marine-grade, heat-shrink butt connectors to ensure a weather-tight seal.

4. 4

   Reassemble and Test

   Reconnect the indicator assembly and reconnect the battery.

5. 5

   Clear Codes

   Turn the ignition on. Some BCM lighting faults will self-clear once the correct load is detected. If not, use a diagnostic scan tool to clear the BCM fault codes.

6. 6

   Verify Operation

   Activate the left turn signal and hazard lights to ensure the indicator flashes normally and the fault code does not return.