2001 Audi A4 1.8T QuattroDecember 17, 2013December 17, 2013My 3rd brake light stays on when headlights are on and I’m getting a loud beep sound when pressing on the brake. Everything works fine when headlights are off what could be the problem? Share Tweet Pinterest Keywords:A4 QuattroElectricalweird 3rd brake light issie 2 thoughts on “2001 Audi A4 1.8T Quattro” Freeautomechanic December 17, 2013 at 3:11 pm Couple of thoughts: 1. Are you sure you’ve got the right bulbs in there? if you’ve got a single filament where a double is supposed to go or vice versa things like that can happen. If you have recently changed bulbs, try changing them again, one of the new bulbs may have an internal short(not likely, but possible). 2. If the car has been in a wreck, you may have a short in the wiring somewhere. 3. A sticking switch or relay may also be a factor. 4. Maybe that module for the headlight reminder is getting activated somehow, or more likely shorted when you press the brake. Maybe determine if pressing the brake is also pressing/snagging a wire that leads to that module. slashnburn December 8, 2014 at 9:10 am Check the wiring that runs through that little rubber trunk from the body to the hinged tailgate. That`s the most likely area for all those circuits to be in close proximity. Plus the PVC coating cracks when old/cold, when added to the constant flexing when you open/close the tailgate. Hope it`s the case, it`s a moderately easy fix with a soldering iron, small lengths of similar sized wires (same colours would be good) and heat shrink tubing. Make sure your new wires are inside the rubber tube, and push any excess wiring into the cavities within the body/tailgate. and seat the locating grooves in the rubber trunking back into their appropriate holes> Good luck… Comments are closed.