Welcome to the forum
Do a "Search Community" above, there has been a lot of talk about water in that area. No cover on mine.

 

Currently going through this problem. It's good that you caught it just before it got worse. My car is down for the moment due to my fuse box being becoming rusted. I've been searching other forums and found this. I hope it helps. Trying it soon as well.
Shop just checked my windows and sunroof. They noticed the drains were clogged but they did not cause the leak over the fuse box. They don't know where it's coming from either. ..

 

Hello. On my 2018 terrain, i sealed all across the top and all around the drivers side tail light with clear silicone. I also done passenger side tail lights well just for good measure. But i ll tell ya somethin else i did too and i hope it helps prevent water from getting in and dripping onto the fuse box. I took a plastic dollar store bag. And wrapped it around the fuse box then tucked the edges down below the back that way water hopefully wont get into the fuse box . I figure if i wrapped it plastic thatd stop the water from getting to the fuse box. Also i put a piece of that carpet lookin stuff (whatever material thats under the spare tire) i tore a couple pieces of that off and stuck one piece above the plastic bag that is covering the fuse box , also put a piece of same stuff wrapped around the front of the fuse box too and just for safe measures. Until i figure out another remedy , i took a plastic lid from a container, thats about 5 inches wide x 8 or 10 inch long and stuck up above that carpet stuff, and slanted it downward toward the door opening of that compartment so that IF water DOES leakin into that area, it hopefully will just run down the plastic lid, but before it gets to the fuses, it has to get thru that plastic lid, thru that half inch carpet, and thru that plastic bag. ..... but ....i wanted to see where that water could possibly be coming from, so before i wrapped the fuse box in plastic, i took a little mirror, stuck in back in there above the fuse box with mirror side pointed upwards. Then i shined a flash light up into the top part of that compartment to see if i could see any holes where water could get thru then drip down onto that vent lookin thing infront of the fuse box .well low n behold. There are 3 or 4 metal brackets, that are apparantly welded in there, that the black plastic cover attatches to. ( would be right under the back window probably) u can see them if you stick a mirror back in there and shine a flashlight up into the top inside above the fuse box. Well i could see 2 octagon open holes in the metal going towards outside of car. Have no clue why theyre there.also right where those brackets are welded i guess if you look into the mirror, you can see 2 little tiny holes, one on each side of that bracket..water MIGHT be gettin thru them holes there , but each bracket has those same two holes one on each side of those brackets. I also noticed a couple more holes in that metal inside why the heck theyd put holes there i have no clue. So i am gonna get some more silicone, a small tube, and get my mirror and my light and try to put silicone over each hole that i can see. I guess itd be easier if you can figure out how to get that black cover off first .then youd be able to access the bracket holes easier. I am gonna try to silicone all them holes, too and hopefully i will have stopped the water from getting in. But the other day after some dew was on the car i lifted the hatchback or liftgate , and i noticed if you look right below the tail light is, where the two pcs metal meets you can see water, very very small amt coming out from the crack where the metal joins. You can see it easier then i can explain it without pics. Im gonna put silicone across that crack as well on both sides and see if thats where water might be dripping in also heck i. Dunno. I wish that fuse box had a cover i could buy that was waterproof. But i will try to upload a couple pictures of how i got my fuse box covered up.in hopes of water not being able to get to the fuses..ok i went out and took some pics to post of where them holes are that i seen on the brackets, also i circled every place i put silicone, like around the tail lights,both sides, around the black plastic plugs, both sides, all around the liftgate door seal , where water might run in off the roof etc, and if you open the liftgate, look up to the right corner where the metal joins, it looked like someone had sealant there before but it wore off (both sides) so i silicones those areas too....i put silicone on then wiped with my finger to make it look as un noticeable as possible. I do however still hafta seal below the tail lights where two pieces of the body meets. U can see in the pics where i drew lines around those places as well. Then last but not least i took pics of how i have the bag wrapped around the fuse box first, then the carpet over top and around and infront of the fuse box then a plastic lid over top of that!! Until i can figure out another remedy...hope all this info helps someone. That factory should have fixed this **** before they ever put that vehicle on the market.. i also have a 2009 chevy equinox but havent had any pblms with leaks anywhere on that..well i guess i cant post pictures here. Will hafta figure out how to do an album then post that i guess .

 

 

Wherever you see silicone on left side. Do other side too...i could only post 10 pics

 

 

 

Heres those holes . Each bracket has 2 holes on each side at top. Then theres annoctagon looking hole on inside too that i ll silicone over but look aroumd inside bc theres more than 1. I.may figure out how to remove the black cober. Take that off first, silicone all holes i see anywhere then put cover back on.