SG5 Foggy tail lights
 

Hi guys,

My Forester left tail light assy is foggy since i got the car recently. I removed it from the car and found a crack in the plastic on the back side of the light assy. I've put enough adhesive silicon to cover that crack. I also dried the light assy with a heater gun.
Installed it on the Forester, but found that issue is still exist, nothing changed. Found no crack on the front (glass) side or back sides.

Do you guys have any ideas what can be done with it except buying a new one?

Thanks.
https://cimg3.ibsrv.net/gimg/www.sco...317daec322.jpg
https://cimg4.ibsrv.net/gimg/www.sco...16949a9ab2.jpg
https://cimg5.ibsrv.net/gimg/www.sco...a047f3e30a.jpg
https://cimg7.ibsrv.net/gimg/www.sco...61cf01054c.jpg
https://cimg8.ibsrv.net/gimg/www.sco...0f72697740.jpg
https://cimg9.ibsrv.net/gimg/www.sco...07835947f6.jpg

Right off it's got condensation in the unit, might need new rubber seals. That go in between light and body work, are there any fitted?

It does not seem to be disassembled easily. I have no experience of changing the rubber seal. Probably needs to be heated well to melt the old seal and make glass removed from the assembly.
What if I just put the adhesive sealant all over, where 'glass' attached to the plastic body?

Think you misunderstood @jaygsi You shouldn't need to open them up just yet. Its the rubber seal that goes on the light and body of the car to stop moisture getting in.

As @NOSSY_89 said, just the gasket that sits behind the light that mounts too the body work. Classic Impreza's never had these, but 2001 onwards models did. So should be the same for yours.

If it's the gasket I think you're on about, only the saloons have those as you access the back of the light through the body. Wagons and Forester's need the light removed to access the back so have no gasket as there is no hole to seal up. Maybe you're on about a small seal around the edge but I can't say I remember one on either my Hawk or Bug wagons.

OP, just because you've used a hot air gun doesn't mean it's dry inside. My Dads Forester had similar problems with the headlights and he tried that. Never worked so I took them apart for a good clean and a bit of paint and they haven't had a problem since. The sealant/glue holding the lenses on is called butyl tape. It's not expensive so if you take the lights apart get yourself some fresh stuff instead of reusing the original stuff and risking leaks.

As above the only penetration through the bodywork is for the wire grommet.
https://cimg7.ibsrv.net/gimg/www.sco...b4538780a1.png

A similar problem raised in 2014
https://www.subaruforester.org/threa...-light.318537/
The back is sonically welded to the housing but "I believe" the two blue "plugs" in the image above are condensation vents
Taking them apart
https://www.subaruforester.org/threa...lights.835219/

Guys, there is nothing wrong with my venting caps and internal separate lights glass enclosures - it is not fogging in there.
Fogging is under the larger 'glass' only, thus, seems like the issue is with that glass and plastic box and fog is usually consentrated on the one side only:
https://cimg9.ibsrv.net/gimg/www.sco...e228b01591.jpg

So I think that I might apply some adhesive sealant around the box, where the glass glued with plastic headlight box.

Update:
I applied Permatex Adhesive Silicon on the enitre permiter to cover the gap between the glass and plastic box, as per the images below (yellow shows where silicon applied) and there is no fogging anymore.

THANK YOU GUYS!

https://cimg4.ibsrv.net/gimg/www.sco...6cb37948ce.jpg
https://cimg5.ibsrv.net/gimg/www.sco...218b5bc11e.png