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.
The IP dimmer switch provides a hard-wired IP dimmer position input to the BCM. Most controls on the instrument panel and elsewhere in the interior of the vehicle are illuminated by the panel lamps dimmer circuit for night visibility. When the Body Control Module (BCM) receives an input requesting illumination, the BCM provides a voltage output to the lamp driver circuit. A ground path is provided to the lamp assemblies through the wiring harness to the body sheet metal.