I have a 2012 ram Laramie with the quad headlamps, and i was wondering if i need a single beam wiring harness, canceller's or both for just the low beams.

 

What you need is a resistor harness to plug into your factory harness. i put low beam and fog lights in my 2012 with quad headlights. high beams still work normally but you need the resistor harness to stop the hid from strobing when on. I purchased mine from carhidkits.com the harness is $50

 

could you post a link im not sure witch one's they are. thanks