i have a 2005 Dodge Ram 2500 cummins. 168xxx miles.I have been dealing with this radio issue since i have bought the truck but dont really pay much attention as i only put on about 500 miles a year on it but would like to get it fixed. When i am on AM/FM radio works fine no issues. When i turn my headlamps on the radio goes to complete static, but if i have the park lamps on and fog lights it works fine. Its something to do with the headlamps. It did it with the factory radio and had replaced it thinking that was the issue and still same issue. i have tried grounding the headlamps to a different source along with the radio and still have same issue. i have tried disconnecting the dimmer wire and still have the issue. its just puzzling to me.

 

Welcome to DF. Moving this to third gen ram section for ya.

 

Are you using LED or Halogen bulbs for the headlights? Sometimes LED bulbs can cause interference with things like the radio...

 

Yep, what Alex said. The ballast on HID and/or LED will emit a signal.

 

If not aftermarket lights, could be a ground issue somewhere.