I had one drivers side tail light go bad from water ...so I pulled a tail light off my other car that was in better condition and switched them around....I SILICONED all the seams around the housing .....we had some really heavy rains recently....the reverse light immediately got fogged over ....pulled the tail light out....it was HALF FULL of water....WTF ? did I do a bad seal job or ???????

 

You can try drilling a couple small drain holes on the underside of the taillight. It won't be perfect but it should help.

 

I imagine the water is intruding through the top where the lens and housing meets.
I’m sure some glue or silicone gasket maker would seal them right up.

 

every inch of the outside seams were siliconed.....now I know why my expensive auxito LEDs kept going bad ....I could drill drain holes.....but I still need to know how water is getting in
I could buy a used housing ....but I would have the same problem again

 

At that rate I’d fully separate them then reseal them. Water must be entering from the top if it’s unable to leak out the bottom.


did you prep the plastic before sealing them with silicone? You Need some auto body solvent before sealing them up.

 

I only cleaned it with detergent n water.....it was quite dirty