I was on AudiDIY the other day and saw a mod involving some simple soldering to bridge the brake light circuits with my rear fog light circuits. 10 minutes later, I had my circuits soldered together on the bulb holders and had them installed. Brake lights worked perfectly, fog lights made an excellent addition in visibility.

Friday evening, my brother told me after following me to the pub that my brake lights are non-operational. I checked my brake light fuses (numbers 22 and 23) and they're good. Checked the bulbs, and the bulbs are good, I just had a taillight bulb burned out. Replaced the bulb, and checked the brake lights again. NOTHING. Frustrated, I took some wire snips and cut the wires I had bridging my brake light/fog light circuits. Now my brake lights still won't work, except for when I turn my rear fog lights on from inside the car.

Anybody have some input? Should I take out the ECU and let it reset itself? No codes have been thrown, I have no warning lights on my dash. Please help, I have no desire to get to know my local police officers especially with my tint and exhaust.

 

Sounds like you might have gotten some solder someplace it shouldn't be. Can you take a picture of the bulb holders?

 

if your referring to the dual brake light, I'm pretty sure you can't use the rear fogs anymore because it turns them all on and they won't go off, obviously until its powered off. But sounds like solder is jumping tracks., or you did a bad solder and it shorted.

 

Here are all of the pictures I took of the bulb holders. All of the bulbs are perfect, and I trimmed the wires I soldered all the way down to the solder itself. I know it's not a pretty soldering job, but I don't think it's too terrible/messy/sloppy either. Just to be clear, when I did the mod, my brake lights worked when I depressed the brake pedal, and they also worked when I activated my rear fog light button. When I turned off my RFL button, the lights would also turn off. This has been a very recent development and I'm just hoping it's something simple. I also noticed that the driver side wiring harness connection is broken, maybe this could have something to do with it? Both brake light fuses are fine, should I check any others?

 

Check for continuity on the lines of the circuit you soldered.

Test if you've got power to the light assembly. Have someone press the brake while you take a voltage meter on the taillight assembly.