i would like to jump in here & ask a question. i have a 1999 a6q (4B, AHA) w/ halogen lights & the passenger side is dimmer than the left(checked harness & right side is only 11.4 volts while the drivers headlight is getting 12.2). i have replaced the turn on switch & no change. i have searched all down by the drivers knee bolster for any burnt wires to the relays & everything looks great. i just haven't been able to locate where the passenger wiring harness connects following it back from the headlight. i checked the stalk & no burnt wires there, so does anyone have an idea or direction that i can check from here?

 

check the voltage right before and right after the relay this will narrow it down for ya

 

There are no headlight relays.