Thefeek

A couple weeks ago my cousin told me I had a brake light out, drivers side. Last night I went to change the bulb and I found it to be operational. Upon further analysis I discovered something not right about how the lights are working. Below is what I have:

Legend - L.turn,L.brake R.brake,R.turn
Off - off off off off
Brake- off off on off
L. Turn- DimFlash,off off off
R. Turn- off off off GoodFlash
LightsOn- Brite on on on
Brake- Brite on Brite on
L. Turn- Brite* on on on
R. Turn- Brite on on GoodFlash

I hope that list makes sense when it's published to the site.
When the running lights are turned on, both filaments of the turn signal bulb are lit solid ie Brite. When i signal left turn I see no difference in illumination, but when I remove the bulb I can see a faint flash in one filament but only looking directly at the bulb. With this crazy state of affairs, I'm left thinking either the J124 Lamp control module, or the turn signal arm in the steering column. Has anyone ever experienced lighting like this?

The lighting is all stock on the car. I have up graded to a 3 spoke sport wheel in the past and am thinking I perhaps did something wrong when I put the S6 equipment in. I deeply appreciate any feedback any can offer.
Mark

Thefeek

Still no luck in troubleshooting this mess. Since I was suspect of the S6 wheel install, I tore apart the steering column. I suspected the speed nuts added to the S4 column switch assembly was too long and contacting some electrical bits inside. When I opened the component to clean things up and search for evidence, the spring pictured decided to leave the area. (see pic) It's been several days and I have not seen the spring. I harvested the same spring from an S6 column assembly, but it doesn't seem to work. I think its too long and places too much pressure on the copper contact band. When I assemble it for a test, the rear driver side lights don't work at all; the rest do.

Thefeek

Just put the steering column back together. The issue wasn't the spring but a bent contact. Now I'm just left with the ole J124 lamp control module rear. Going to see if I can find one for cheap.

Ebay has one that is almost the same except for one letter off from the original part number. The part number for my relay is: 4A0-919-471-A. The one on Ebay is 4B0-919-471-A. Does anyone know the significance of the second digit in Audi's part numbering process?

UrS4boy

The first two letters/numbers tend to refer to the chassis design, i.e. our "C4" cars are to the electronic parts catalogues, "4A". But that seems to be hit and miss, especially on electrical parts.

4B0-919-471-A is supposed to be a lamp control module with a "387" label on it. It is the latest version, as documented HERE (read all the way down)

Thefeek

Wow. That's quite the tale that you and Kate put together. There's a 4B0 919 471 on ebay for $15. I'm going to take the chance that both it works and will function in my car. Thanks for the help. Once I have the relay installed and functioning, I'm going to disassemble the "302" and see what went wrong. In the trades we call it destructive testing. Thanks again!
Mark

Thefeek

I bought a replacement J124 lamp control module from Ebay. It was the current replacement part with "387" on the top. When I installed and tested, the problem still remained. Then I took the left turn signal bulb out ( again ) and reinstalled it, then it worked correctly.

I disassembled that twice and attacked it with contact cleaner and abrasives to no avail. Now it works. C'est la vie with this car. Below is a picture of the component side of the original "302" J124 module in case there's an EE on the forum. I couldn't see any signs of damage or anything out of the ordinary. On to the next project,,,
M

UrS4boy

Got a photo of the other side, with the printed circuit board? There might be a crack in one of the traces.

Thefeek

Yes, I do. There is a discoloration of an area, but I think it's left over flux. There are other spots that look the same. The suspect area I wrote "Here" on the pic.
Enjoy,