Theory Of Operation

WARNING: This page is about a different car, the 2014 RAM 3500 HD and 2014 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Incandescent Rear Fog Lamps: When the Body Control Module (BCM) receives an input signal from the Rear Fog Lamp Switch, requesting Rear Fog Lamp illumination, the BCM provides a Pulse Width Modulated (PWM) voltage output, through the Left and Right Rear Fog Lamp Feed Circuits, to the Left and Right Rear Fog Lamps. A separate ground circuit is provided to the Left and Right Rear Fog Lamps through the wiring harness to the body sheet metal.

LED Rear Fog Lamps: When the Body Control Module (BCM) receives an input signal from the Rear Fog Lamp Switch, requesting Rear Fog Lamp illumination, the BCM provides a voltage signal, through the Left and Right Rear Fog Lamp Feed Circuits, to activate the Left and Right Rear Fog Lamps. A separate ground circuit is provided to the Left and Right Rear Fog Lamps through the wiring harness to the body sheet metal.