Random exterior lights coming on on car.

[Rampage]

Hi, I’ve had a bad leaking sunroof, water is coming through the lights in the headlining above the sunvisor. The sunvisor is full of water too.
The drivers side footwell is soaked, but I’m not sure how the water has got there, a-piller seems dry.

Random lights seem to be coming on on the car.
The high level brake light has been on, so has one of the rear lights, currently just the drivers side front fog light is on. It’s on when the car is locked and is draining the battery.
Presumably water has got on some electronics and is causing this. Any idea what I should be looking for or? Is there anything above the headlining that can cause it?

Thanks.

 

[300bhpdaily]

You just said you have a bad leaking sunroof. That’s the cause of the problem. it must of leaked down the headlining and behind the pillar then behind the dash where the gateway module is and then finally onto the floor. The damage is done now. How long have you known the sun roof has been leaking?

 

[Rampage]

What’s the gateway module?

I didn’t know it was leaking until my wife told me the lights were on.
Although over Christmas I noticed the flap that covers the mirror in the sun visor went stiff, that would have been the water getting in because it hardly moves now.

 

[300bhpdaily]

It’s a control module behind the dash usually that controls parts of the car. Ie lights and electrical systems. Best bet is to take it to a good vw specific garage. Doesn’t have to be main dealer. What we’d do at work is check the codes see if it’ll give us a heads up. But normally it doesn’t you’ll need to locate the gateway and see if it’s flooded or water damaged. If it is instead of buying new maybe get one from eBay and have it coded to your car. But the most important thing you do is find the leak and repair it so the new parts don’t get wet and do it all over again. I’ll be honest we’ve done it at work for a customer and it’s a very expensive process due to the amount of time it takes to diag the cause. Water testing etc to remedy the leak. But you’ll save money on buying a used unit off eBay.

that’s provided what I’m saying is the cause. If it’s not I do apologise, I’m just speaking from my previous experience on this kinda problem while working for VW.

 

[Rampage]

Just looked it up, makes sense that the gateway module is damp after reading what it does.

Presumably it’s near the OBD2 socket?

 

[Rampage]

Thanks.

 

[300bhpdaily]

normally it’s behind the dash close to the centre point of the dash but not sure on the location on your actual car mate. It’s a horrible situation unless you have some kinda warranty on the car.

 

[Rampage]

Yep, it was above the ODB2 plug. Pretty wet and dirty inside.
Thanks.

 

[Rampage]

Well, I took it out, washed it under warm water, shook dry, sprayed with IPA, brushed gently with toothbrush, and blew off gently with compressed air.
It seems to have solved everything except the 3rd brake light, but that could be something else.