Theory Of Operation
WARNING: This page is about a different car, the 2024 RAM ProMaster EV. However, it is still accessible from the selected car via links, so may be relevant.
When the Body Control Module (BCM) receives an input from the Headlamp Switch, requesting Park Lamp illumination, the BCM provides a voltage output to the License Plate Lamp Driver circuit. A ground path is provided to the Lamp Assemblies through the wiring harness to the body sheet metal.