Condensation in tail light

[lloyds]

I know it has been brought up before, but wondering if anyone had any luck on a fix. Tesla replaced my light once and after washing it today it fogged up again. I would rather not have to go in again for something that they cannot fix right. TIA

 

[nigeldodd]

A week ago I took mine in for fungus growth in lower boot area. My rear lights suffer condensation however I was told that there needed to be actual water, by which I presume they meant a pool of water, in the light fitting for them to consider replacement.

Personally I feel that any moisture is a potential rust problem.

 

[jeremymc7]

I thought the newer lights had a small hole to allow ventilation (and draining). Seems like a half baked idea compared to proper sealing. But then 2021 M3 only just finally got a fix for water in the trunk between the rear window and trunk lid. That took 3 years to fix and I still think that’s kind of a half baked solution as well if you look at the specific fix involved.

 

[pianomankd]

I thought the newer lights had a small hole to allow ventilation (and draining). .

They do. Mine does. Doesn't help.

 

[Battpower]

MS R, 2019.

There is a back story here I am sure. Just don't know what it is and quite possibly involves a combination of factors which always makes it tricky to get to the bottom of.

I have had other non Tesla EV's and none have had same condensation issues so coincidental with change of weather (cooler ambient temps).

Especially an issue for b-pillar cams.

May be related to reduced airflow to reduce heat loss.

May be related to poor assembly and water ingress.

May be California based design & testing.

It's not just about external lights, but do other cars with efficient (low heat) lighting suffer condensation problems? Not in my experience.

Also, cabin heating obviously different for EV's but rear lights and driving lights seem to fog up regardless of cabin environment.

 

[nigeldodd]

Is it known whether the light assembly is open at the back? Presumably it must be which is why the moisture gets in. After Tesla replaced the boot seal I have been using a small dehumidifier in the boot while parked at home. This draws out about a cup of water in 24hrs. In the UK the relative humidity is about 60% which will explain some of the water.

It is only by using the dehumidifier in the boot that the lights become free of condensation.

 

[pnwadventures]

Resurrecting an old thread: I finally decided to try the solution outlined here to fix my tail light condensation:

It’s only been one day, but so far so good. Will report results after a week.

The procedure to remove/reinstall the lights was very straightforward. Sealing them with liquid tape was also pretty simple. However, getting the trim clips out without breaking some was extremely difficult. I highly recommend actually buying a clip removal tool (and maybe some extra clips) before undertaking this effort.

Next up: trying the same fix with the front fog lights.

 

[Tez~La]

Great video and instructions! Job well done.
The only thing I could not find was the boot, did not even find shoes or sandals.

 

[pnwadventures]

Update: I sealed the hell out of those lights and still getting a little bit of condensation in the housing following a trip through the car wash.

 

[danaleighton]

Update: I sealed the hell out of those lights and still getting a little bit of condensation in the housing following a trip through the car wash.

I talked with the mobile service tech about this. As Nigeldodd said, the tech confirmed there is a hole in the light housing, and that especially under pressure water will sometimes get in and cause condensation. He said as long as it's gone in a day, it's fine. If there is actual water (not mild condensation on the surface) in the housing that is a service issue.

 

[Macb00kemdanno]

I have what I guess is "mild condensation." Just noticed it today, but I last went through the carwash Tuesday of last week. I noticed on the driver's side after I washed the car in my driveway about a month ago, but it went away the next day. Maybe it's still lingering because it's so cold outside? Who knows!

 

[Battpower]

Cold outside, any raised humidity inside = biggest chance of condensation.

 

[RedMod3]

Resurrecting an old thread: I finally decided to try the solution outlined here to fix my tail light condensation:

It’s only been one day, but so far so good. Will report results after a week.

The procedure to remove/reinstall the lights was very straightforward. Sealing them with liquid tape was also pretty simple. However, getting the trim clips out without breaking some was extremely difficult. I highly recommend actually buying a clip removal tool (and maybe some extra clips) before undertaking this effort.

Next up: trying the same fix with the front fog lights.

Thanks, I did get a ranger out to replace mine, but having watched your video, I'll repair my broken unit and keep it as a spare.

 

[h2oAok]

It is a quality issue with Tesla's supplier for the rear tail lights. The manufacturer does a terrible job of fusing the two halves of the tail light. Tesla doesn't seem to be concerned about the quality control issue, probably because lower cost & standards go hand in hand. This is also why some new replacement tail lights experience the same issue. This issue is not exclusive to Tesla tail lights but it is common with manufacturers that accept poor standards from their suppliers.

 

[pnwadventures]

It is a quality issue with Tesla's supplier for the rear tail lights. The manufacturer does a terrible job of fusing the two halves of the tail light. Tesla doesn't seem to be concerned about the quality control issue, probably because lower cost & standards go hand in hand. This is also why some new replacement tail lights experience the same issue. This issue is not exclusive to Tesla tail lights but it is common with manufacturers that accept poor standards from their suppliers.

FWIW, front fogs do it, too.