I used to have this problem. To the point there was so much water in the bottom, a bulb shorted out. Someone suggested I drill tiny holes in the bottom to let it drain. I haven’t had any problems since. I still wish I knew how water gets in there in the first place though.
@Keir
Worn out gasket seals. You might be able to find seal replacements online or just replace the whole thing pretty cheap.
The little bar light above the back windshield on my truck leaked and I just replaced it with a new seal from Amazon.
@Keir
This^ be thankfully you don’t have BLIS sensors and LED taillights. Those units are $1700 a piece for factory 5-600 at a scrapyard and there’s no aftermarket for the BLIS sensors.
Easy fix- you can get cheap aftermarket units on Amazon for under $100 or call a local junkyard. It’s 2 screws and then the harness unclips, bulbs turn out and boom done.
Avery said:
Easy fix- you can get cheap aftermarket units on Amazon for under $100 or call a local junkyard. It’s 2 screws and then the harness unclips, bulbs turn out and boom done.
Thanks!
I’d drill a tiny hole in the lowest spot of the tail light to let the water out so it doesn’t rot the wiring harness
I second the comment, before mine or just put up with it.
I had the same problem. By the time I discovered it, the chrome plating had started to peel off. I drilled a hole in the seam to drain the water. The leak occurs where the two pieces of plastic are welded together. I replaced the light eventually.
Blinker fluid
Anyone have a link to one they purchased off Amazon that they like?
Remove the light and take it inside in the A/C until the moisture is gone. Get some clear sealant and run a bead around everything including where the bulb attaches. It worked for me.
Weston said:
Remove the light and take it inside in the A/C until the moisture is gone. Get some clear sealant and run a bead around everything including where the bulb attaches. It worked for me.
I’ll second this, except I would leave the light outside (if it’s warm) in the sunlight. Shouldn’t take more than an hour or two to evaporate, then put the sealant around the edges.
Got mine for $40 off Amazon and took 15 minutes to swap out… 7 of which was finding a 10mm wrench.
This happened few weeks ago , just get a replacement otherwise the water and moisture will burn the light bulbs out
Just wait a bit. Someone on here will jump in and say it’s perfectly normal and reference the manual.
Ah, topped off blinker fluid 
Moisture in your moms taillight