Need Brake Light wiring diagram help!

[stolnheartdealr]

So the brake light closest to the trunk has been out since I bought the car years ago. This doesn't cause a 'light out warning' in the cluster and all the other lights on the driver's side rear work fine, it is only this one brake light in the passenger side that's out. The bulb is good because I can put it in the other tail light and it will work.

Since it's only this single filament bulb that's an issue it has to be the positive connection which is pin 6 on the plug and on the brake light housing side the pin is labeled "NES". I have gone as far as cutting the insulation on this wire to see if voltage existed however nothing. I checked resistence between pin 6 and ground and the connection is open like it should be so I can say the pin isn't shorted somewhere. I also checked continuity between the cut I made in the wire's insulation and the contact in the plug side and continuity is good.

So it's not the plug and it's not the lamp and it's not shorted so maybe it's just disconnected somewhere???

I have read up on brake light electrical issues for this car but I can't seem to find how this particular bulb is identified in the diagrams because I've not yet found one that identifies a gray/white wire that is connected to a bulb so far. I also understand that this plug leads to the J519 power supply module underneath the cluster on the driver's side. Am I right about that? However without knowing what this light is called in the diagrams even a pin out for that doesn't do me a whole lot of good. I also can't say if my car is "high line" or "low line" electrical. I've seen that mentioned as being important to finding the right wiring diagram.

If anyone is good at tracing wires in the funky diagrams that audi uses I could sure use (and would greatly appreciate) the help.

Thanks!

[Let it snow]

The only gray /white wire I see goes to the left rear fog light. Is it a brake light or the running light?

[stolnheartdealr]

The only gray /white wire I see goes to the left rear fog light. Is it a brake light or the running light?

It seems you're right. The working driver side fog is only active if I throw my headlight switch full on and pull out two detents. One detent has the front fogs active and the second activates rear fogs. I always turn my lights on this way so I never noticed.

[Let it snow]

Yup it just turns on that one rear fog light. I guess it is for safety but if you ask me I think it is weird to have any rear fog lights.

[old guy]

Clicky click®

[stolnheartdealr]

Clicky click®

Thanks, did not know, seems so odd for a vehicle to have only one side lit. I'm finally prompted to 'fix' this because I have just been pulled over for the second time with the cop telling me my brake light is out.

Is my model really only one fog light? Seems so odd that the right side is wired.

Also, found this Audi A4 Basic Equipment Lowline 2003.pdf

[old guy]

The wiring is in place for either right hand or left hand drive.

[stolnheartdealr]

The wiring is in place for either right hand or left hand drive.

I wish they would have left the wiring in place for my heated seats!!! ah well

Thanks a ton guys for not flaming me :D I have seen other b6's with both working and there was a bulb installed from day one which didn't help my misunderstanding :/

[diagnosticator]

The reason you are getting pulled over for a tail light out, is because you are turning the rear fog light ON when you turn on your headlights. Stop pulling out the headlight switch when you turn the headlights ON.

All N.A. market spec B6 A4s are Highline electrical systems.

The wiring diagrams are easy to read, once you understand a few of the fundamental rules involved. First, the layout of the diagram is with + Battery 12 vdc, at the top of the diagram show by the solid line or bar horizontal across the top of the diagram. The various circuits to the devices and electrical components are vertical lines dropping down from the +BATT "30" buss at the top of the diagram, called Current Tracks. The current flow is from the top of the diagram to the bottom of the diagram. The bottom line is the chassis ground. Vertical lines from the components shown in the diagram view field, continue to the bottom line showing connection to chassis ground. Along the bottom of the diagram, are numbers called Currant Tracks numbers. when a circuit line ends in boxed number, that refers to the current track number where the circuit continues. Find the current track number on the bottom then look up and find the current track where the boxed number beginning current track number and that is the circuit you are working with. Both current track numbers in the boxes refer to the other current track number. Important information for each diagram page, is shown on the diagram as legend side notes.

There are other rules also, but once you learn the basic rules, reading the wiring diagrams becomes second nature like reading text. All of the rules for reading the wiring diagrams is in the front pages of a model platform diagrams.

You can purchase a 24 hour subscription to access the Audi Service manuals and wiring diagrams, from Audi erwin at: https://erwin.audiusa.com/erwin/. After you login and locate the content you need, you can download and print as much of the manual as you want during the 24 hours access.

Save all the downloaded PDF files in a folder named "Audi Service" or? Cost is about $30.00

[stolnheartdealr]

The reason you are getting pulled over for a tail light out, is because you are turning the rear fog light ON when you turn on your headlights. Stop pulling out the headlight switch when you turn the headlights ON.

Yup, I've deduced this thanks to the help of this thread, it was just confusing as like I said, I've seen other b6's with dual fogs, it's wired, there was a bulb in it when I purchased the car and I thought it was a 'running' brake light and not a fog light. Obviously I'm not the only one confused by this or I wouldn't have been pulled over twice for it :/ lesson learned.

All N.A. market spec B6 A4s are Highline electrical systems.

Good to know, all the threads I've read made it seem like a semi-complex matter about disconnecting components and seeing what errors were reported if any. I'm guessing in other areas both systems exist.

The wiring diagrams are easy to read, once you understand a few of the fundamental rules involved. First, the layout of the diagram is with + Battery 12 vdc, at the top of the diagram show by the solid line or bar horizontal across the top of the diagram. The various circuits to the devices and electrical components are vertical lines dropping down from the +BATT "30" buss at the top of the diagram, called Current Tracks. The current flow is from the top of the diagram to the bottom of the diagram. The bottom line is the chassis ground. Vertical lines from the components shown in the diagram view field, continue to the bottom line showing connection to chassis ground. Along the bottom of the diagram, are numbers called Currant Tracks numbers. when a circuit line ends in boxed number, that refers to the current track number where the circuit continues. Find the current track number on the bottom then look up and find the current track where the boxed number beginning current track number and that is the circuit you are working with. Both current track numbers in the boxes refer to the other current track number. Important information for each diagram page, is shown on the diagram as legend side notes.

There are other rules also, but once you learn the basic rules, reading the wiring diagrams becomes second nature like reading text. All of the rules for reading the wiring diagrams is in the front pages of a model platform diagrams.

This is great help, I gathered about this much from the schematic research I was doing before creating this thread however you clarified and pointed some things out I didn't know.

You can purchase a 24 hour subscription to access the Audi Service manuals and wiring diagrams, from Audi erwin at: https://erwin.audiusa.com/erwin/. After you login and locate the content you need, you can download and print as much of the manual as you want during the 24 hours access.

Save all the downloaded PDF files in a folder named "Audi Service" or? Cost is about $30.00

Awesome I may do this, do you get online access to an 'ETKA' or similar with this, that's useful. I had signed up for a similar service that allowed me access to a bentley and some TSB's related to the car I subscribed to, however it is a bit of a pain to navigate and I keep having to search my email to remember what it is. Just searched quickly, the service I have is AllDataDIY.