Well in theory the canbus has a built in resistor to mimic a halogen bulb. I'm pulling power from the battery so this just trick the computer into thinking everything's fine. While the capacitor link to my understanding just regulates the pulsing voltage. (PWM) This just regulates the flickering from the ballasts by taking that pulsing voltage, storing it, and releasing it slowly. They said the can-bus is used instead of a relay but I have one canbus going into the relay to trigger things on and off and a canbus plugged into the other side to just cancel headlight out messages.