I am having a problem with water in the cargo area of my 99 4runner and it appears to be coming in around the vent area. I removed the plastic trim to look behind the vent and noticed that this vent just vents into the space between the body and trim, it doesn’t actually go anywhere. Behind the trim is also a small plastic drip pan that has a clear plastic hose that goes forward and disappears somewhere. Why do I have a drip pan inside the vehicle and what is it draining? My thought was that the drip pan may run over or spill while I am driving and the water would dampen the carpet on that side.

 

Sorry I don't it could lead to this vent:
https://www.yotatech.com/forums/f2/3...estion-145062/

Or maybe your roof rack is leaking if the seals on screws were broken (if f.ex you removed the end cap and didn't reseal it).

 

That vent goes to the outside, down below the floor level it comes out behind the side part of the bumper. I guess the drain pan is to catch any water that manages to get in. I would put some water in the pan and see if it drains out through the hose. If it doesn't then your theory is probably correct, and then you'll have to clear the hose.

 

u haz moonroof ? it haz 4 drain tubes. they could be leaking

 

Same issue with my runner yet only a little water near the rear cargo carpet area (only sometimes)
Do you have any any pictures of the possible cause?

 

I had the same problem. It turned out that the clear hose was not snapped into the drip pan. When it rained, rather than the water draining into the drip pan it would leak into the cargo area. If that is not your problem, you may want to check to see if the drip pan is not clogged and is draining properly. You can test it by simply opening your sunroof and pouring water into the sunroof "gutter". If it is draining properly you should see water puddling behind the driver's side rear wheel. Good luck!