Electrical Issue - Long

[R Evolution1]

I have STFA and have found no response other than "check the fuses/check the bulbs", well I have checked the fuses and they are good (for both Central Convenience fuses #38 & #24 I believe) and I have tested every bulb and they all work. I am out of ideas as to what or where to look to in resolving this issue:

No Interior Lights - that means no map lights, no dome lights for front Pass. Driver and rear pass. or trunk, this also includes the driver and front passenger puddle lights.

The weird part is that the Glove Box light works and the rear passengers (both sides) puddle lights work and all the lights on the doors themselves work. I have checked codes with a Vag-Com and have found none, the central convenience controller is responsive and therefore I assume it is not the culprit (I ran measuring blocks for the controller and according the the controller the lights are "ON" when I open a door, turn on the lights, etc).

Another interesting and perhaps related issue is that the Auto-Dimming function was not working for the rear view mirror, when I removed the power connection going to the dome lights (the entire switch assembly which also houses the sunroof dial) it started dimming again but as soon as I connected the power back to the dome lights it would not dim but it does show the compass and a green light indicating it has power.

I am at a loss....

[R Evolution1]

Update:
I have checked voltage on the terminals connecting the bulbs in place: max reading I get is 3.6v (for all lights front to back) whereas the working light in the glovebox comes back @ 12v, I get no voltage reading on puddle light for driver....

Anyone??

[Dopefish]

Reading your issue I thought you might have a faulty coding on your Convenience module but seeing that huge voltage drop on a majority of your lighting circuit would point to a high-resistance or short somewhere.

I'm not too familiar with the wiring of these cars yet but I'd start from the source power for the lighting and back trace to each light until you source the wire at fault.

[Audi Skate Snow]

Reading your issue I thought you might have a faulty coding on your Convenience module but seeing that huge voltage drop on a majority of your lighting circuit would point to a high-resistance or short somewhere.

I'm not too familiar with the wiring of these cars yet but I'd start from the source power for the lighting and back trace to each light until you source the wire at fault.

correct... if your getting voltage but its a low reading voltage then most likely there is high resistance prolly on the ground side. Check for any loose connections or building up etc..

ill see if i can get you a diagram (for OP)

[R Evolution1]

UPDATE:

I have taken out the Glovebox, instrument panel, drivers A-Pillar cover and dead pedal cover (to expose all the fuses on the drivers side) and have checked all ground connections I could find behind these locations, all of which were good, clean and tight. All connections running to all lights were ok as well, the only one I did not check was the passenger vanity mirror.

Something strange that I noticed is that the glovebox light feeds off the same connection as the front passenger puddle light, the glovebox light works but the puddle light does not

After all my investigation into this matter I will try and swap out the entire dome light switch assembly to see if that's the cause. Only because when I plug it in the rear view mirror stops dimming, maybe thats what is pulling more current than it needs to and therefore preventing the other lights from turning on??

Doesn't really explain why no voltage is detected on the drivers puddle light, which seems to run off the Diagnostics port -> which runs to the huge ass bundle of wires zip tied to the side of the car.

[R Evolution1]

Bringing this issue back from the dead!

I have been living with no interior lights for the last 4 years, I got to frustrated with troubleshooting this issue and decided to live with it - oh well.

Now I am going back at it to make sure that I get a resolution and keep this thread updated with my results, especially seeing how there are a few other threads where the issues were the same (No Dome light/map light/vanity/Auto Dim). I wonder if Synthetik or PhunkFX have been able to get theirs to work?

The one thing I was able to figure out is that the car must know when the lights (either dome or map) are on because after messing with the on/off buttons the auto-dimming rear view mirror started working again. My guess is that I must have had one of the map lights in the "on" position and thus caused the auto dimming feature to be deactivated, and when the lights themselves don't work it's a crap shoot as to figure out which one of the 4 map lights it was.

I had stated before that maybe the entire dome light assembly with sunroof switch was to blame. I purchased another one and installed it in hopes of getting the issue resolved... and still no interior lights.

I am in the process of replacing all the fuses in hopes of finding the problem there (all fuses look fine?!) especially since this thread Clicky Clicky! required a new fuse in order to function again.

Synthetik or PhunkFX you guys still around????

[R Evolution1]

Last night I replaced every single fuse in the drivers side fuse box, yeah every single one, just for the heck of it... AND

Nothing.

Are there anymore fuses that I can replace?

[R Evolution1]

I HAVE LIGHTS!!!!!!

I figured out what was wrong and it was a $2.99 fix!!! The wiring loom going to the central convenience module had several wires degraded and corroded, I took pictures and will post it up soon. Soo happy that the lights are finally working again

[milan2k13]

I HAVE LIGHTS!!!!!!

I figured out what was wrong and it was a $2.99 fix!!! The wiring loom going to the central convenience module had several wires degraded and corroded, I took pictures and will post it up soon. Soo happy that the lights are finally working again

Bet it feels like you came out of a cave haha jk. Good job.

[R Evolution1]

I should have listened to you Dopefish over 5 years ago!!!

Reading your issue I thought you might have a faulty coding on your Convenience module but seeing that huge voltage drop on a majority of your lighting circuit would point to a high-resistance or short somewhere.

I'm not too familiar with the wiring of these cars yet but I'd start from the source power for the lighting and back trace to each light until you source the wire at fault.

Here is what the wire loom coming out of the central convenience module looked like:



A little tug on the loom and the corrosion started to show its face:



What the heck is going on?????

[R Evolution1]

Here is what the loom looked like underneath the plastic shielding, which was a PITA to take off:



Any Idesas as to why it got like this???

My guess is that the loom was rubbing on the edge of the plastic shield which caused one of the wires to be exposed and thus caused the loom to overheat and corrode? IDK???

[gmudan]

pics arnt showing ^
edit-nvm

[R Evolution1]

Here is a close up of the the loom where it made contact with the edge of the plastic shielding, however most of the corrosion seemed to happen inside the shielding:

[R Evolution1]

The funny/strange part is that a Vag-Com scan of the module shows no error at all, in-fact I could re-code it to my hearts content and showed no error. The corrosion just effected the dome lights, cargo area lights and front passenger and driver puddle lights, all the other lights worked fine such as the door panel lights and rear passenger puddle lights including the glove box light.



So if you are currently experiencing a strange interior light issue that is intermittent or permanent I strongly suggest that you check your wiring loom coming out of the convenience module located underneath the drivers seat, it may have started to corrode!!!

[R Evolution1]

And finally after 5 years of troubleshooting the wrong way I finally have lights!!! Now it's time to do a LED upgrade and create more electrical issues, heh heh



Looks like I need to replace the drivers side map light bulb

[R Evolution1]

Last picture, I promise



Yay! Lights!!

[MurkyRivers_A4]

Good job man. I bet it feels good to have fixed this after so many years. Im gonna bookmark this page in case I ever come across the same issue.

[R Evolution1]

Good job man. I bet it feels good to have fixed this after so many years. Im gonna bookmark this page in case I ever come across the same issue.

I can't even explain how good it feels to have lights again, it seems so stupid to be excited for interior lights but after this long..... LIGHTS!! I wonder if Synthetik or PhunkFX are still around, they had similar issues and I was following their thread for a while, maybe they have a corroded loom as well... and if so IT'S SUCH AN EASY FIX GUYS! The hardest part was just getting the loom itself.

The only thing that I can't understand is how the hell did this happen in the first place

[diagnosticator]

The corrosion is the result of water getting into the wiring at some point in the past. If you drive in a very rainy season, check under the carpet for water. This can be the result of blocked drains in the plenum under the windshield. You can also check the drains using a garden hose without a nozzle, run on the windshield and see that all water that runs off the windshield into the plenum drains out of the plenum as fast as it enters the plenum. There are two drains, one under the battery and the other on the left side under the brake booster. Audi issued a TSB to remove the duck bill valves from the drains.

[R Evolution1]

The corrosion is the result of water getting into the wiring at some point in the past. If you drive in a very rainy season, check under the carpet for water. This can be the result of blocked drains in the plenum under the windshield. You can also check the drains using a garden hose without a nozzle, run on the windshield and see that all water that runs off the windshield into the plenum drains out of the plenum as fast as it enters the plenum. There are two drains, one under the battery and the other on the left side under the brake booster. Audi issued a TSB to remove the duck bill valves from the drains.

I will check that out, thanks diagnosticator!

Since the drivers seat was out I decided to remove all the seats and clean the interior, it's so dirty

Before Drivers side



Before Passenger side



After Passenger side



I didn't take a picture of the drivers side before putting the seat back in, but, CLEAN CAR AND INTERIOR LIGHTS!

It feels good

[Kodymfk]

I am having a problem with my ccm I think? My drivers side had gotten flooded and now my dash keeps telling me my hood is open when it is not and, my gas door will not open now. Are these ran by the ccm under my drivers seat?