Dome/Vanity/Map lights - sunroof drains

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
I'm having an issue on my recently acquired 2013 Passat. The overhead lights including the visor mirror lights do not work. I tried tracing out which fuse may be affecting the issue, but could not find continuity between the red/blue wire of the visor light and any fuse terminal at the dash or under the hood. Then, I dug deep online and found out it is likely caused by an underlying sunroof drain leak.

I'm thinking possible culprits at this point are a corroded connection (I saw one user post that the red/blue wires all tie together at a point common for a drain leak to affect), or a faulty CCM.

I tried to snake the drain clean with a .095 trimmer string and also a 5/32" (or so) vinyl wrapped steel cable. Both meet resistance near the bottom of the A pillars on either side of the vehicle. There are some hints online about where the problematic duckbills are located, but I couldn't find them at a quick glance.

Can someone tell me in detail where I should be looking for the drain ends for both the front and rear sunroof drains?

I'm planning on removing the A pillar covers to see what's going on behind them, and there are pretty good instructions on here to do that. I may also decide to pull the headliner to make sure those connections are good, but there is very little instruction on how to do that.

Can anyone explain the best way to remove the headliner? I have not had very much luck with removing interior panels in the past, and am worried about breaking clips off.
 

showdown 42

Veteran Member
Joined
Feb 16, 2012
Location
naples,FL
TDI
2016 TDI touareg
How about using your warranty, yOu did pay for it. Digging around in a car under warranty isn't always the best idea.
 

vw_norm

Gone, but not forgotten.
Joined
Jul 22, 2012
Location
Hawaii
TDI
2012 NMS TDI SEL Platinum Gray w/moonrock
I've pulled the A pillar covers and can tell you that the drain tubes continue down under the dash. I did not see where they exit. You might have better luck (and easier time of it) by removing the air dam between the engine compartment and windshield as it appears that the hoses exit below the windshield into that area from the body exterior manual. The rear drains exit through the rear wheel wells.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
I've seen a couple posts where someone shorted out a map light, etc and the BCM will not try to light it again. Have you reset everything with VCDS (full scan would help), or at least pulled the battery to reset? Worth a shot.

On earlier cars the sunroof drain is near the door hinges - I don't have a sunroof (manual trans car), so I can't help much there
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
Norm,

Thanks for the info. I'll take that cowl off and see what I find. I tried peeking in there yesterday, but didn't see anything notable.

GForce,

My car was in the dealership yesterday for the headlight recall. I noticed my MPG average was reset when I got the car back. Do you think they may have done a reset as part of that recall?

Keep that info coming....
 

Vmwalker

Well-known member
Joined
Jul 20, 2011
Location
Gahanna, Oh
TDI
2013 Passet TDI SEL Premium Reflex/Moonrock
.............. I noticed my MPG average was reset when I got the car back. Do you think they may have done a reset as part of that recall....
The battery is disconnected as a step in the headlight recall.
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
That makes sense. Would I still have continuity between the red/blue wire and its fuse terminal whether or not the car needs a VCDS reset? I remember seeing somewhere that the ground is used as the switch leg.

I did end up finding the front drains and was able to snake upward through them and floss the drain lines. I didn't see water start running out of them so I'm thinking they weren't clogged, and there were no duckbills on them. I do suspect a leak somewhere though. Where's the best place to start looking for a leak?
 

Cincy_TDI

Veteran Member
Joined
Jul 30, 2013
Location
Cincy
TDI
Passat SE TDI
For the sunroof drain, has anyone tried or can you use compressed air from a compressor at maybe 35-40 lbs?
Just a thought, don't want to blow any connections apart
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
For the sunroof drain, has anyone tried or can you use compressed air from a compressor at maybe 35-40 lbs?
Just a thought, don't want to blow any connections apart
People have popped the connections apart behind the headliner/pilar trim trying that. Weed wacker line seems to work well.

I'm possitive that I've read of at least two other people here with leaks behind the headliner. IIRC it was right near the sunroof assy - front corners maybe?
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
GForce,

I read that thread previously, and just today removed the cover between the door and the fuse panel. I could see the drain junction, and it did not leak when I poured water around the sunroof. However, I did snake the drain a few days ago, so there may have BEEN a backup issue.

I'm going to silicone around the drain tube, but my main concern now is still the electrical issue involving the overhead lights. I can see the wire bundle that comes through the A pillar from above but can't isolate the red/white wire enough to poke through its sheathing to test continuity from above (i was mistaken when I previously said red/blue - that's the ground). I went to take the A-pillar cover off to get a better reach at the wiring, but I was using a Torx socket and could not reach the recessed bolt of the A pillar with it. I just picked up a Torx screwdriver set and will get back at it later this week.

Update to follow...
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
Gotcha... sounds like you got things mostly covered. Sounds like you have the wiring diagram. Let me know if you do not.

Kinda related - I did have a VW brought to me a couple years ago for a similar problem. There was a broken wire behind the fuse box that ran up to the overhead console.
 
Top