I run HID in my low/highs. I have the quad lamps so separate bulbs each.
I run a relay harness each (2 harnesses in total).I only run 1 Error Code Eliminator per harness, I think it's my feed/switch source, than the other side of the error code goes to my relay.
Without that error code, lights turn on when the truck is off, but once I start the truck and turn the lights on, starts flickering and don't even work half the time.
I have been running this setup for over 2 years without any issues. Only thing I have done was a retrofit on my lights but just installed new bulbs and used all my old harnesses. Worked fine.
Check out www . ddmtuning .com/ (no spaces)
This is where I order all my lights from, well HIDs.
NOTE: I ran HIDs in my fogs, no error code eliminators and everything worked 100%. Than I retrofitted them to LED so they left. Not sure if 2012 they changed the fogs to the canbus system??