Hey all, so I've had this problem the entire time I've owned the car and I'm curious to know if it's just a feature or if something is up, as I can't find anything on what I got going on
Basically the air vent left of the steering wheel is very weak, but only that one? The HVAC works perfectly fine otherwise and every other vent blows air as one would expect, it's just that one vent in particular that sucks ass; even with the fan on the 2nd setting you can barely feel a thing coming from there - I'd say probably 50% of what's coming out the other 3 up top. Just replaced the blower motor and though it's much stronger the problem still persists. The little cut-off switch below will stop air coming through altogether so I don't think it's stuck, and I've already double checked that the ducts are still connected - tried to feel for a leak while down there (perhaps where the ducting meets) and couldn't find much. The vent located beneath the steering wheel blows air a little weaker than the others, but it's not the same size/shape either and it's not nearly as bad as the one in question
Anybody know what I'm talking about? Any ideas on how else to troubleshoot it? It doesn't seem like there's a whole lot going on down there so I'm not really sure where else to look. Any advice is appreciated

i think it depends on the mode setting. i noticed that when on the front mode setting, most of the air goes through the center vents, driver's knee, and a little in the side vents. but in another mode, the side vents blow more air

I had this same issue. I looked at the ducts that run under the dash and found that Toyota, in one of their few design errors, used poor quality/too thin/wrong materials in the plastic used construct the ducts. The ducts warp and shrink, allowing air gaps to form at the junctions. My worst gap was right below the far left vent; I wrapped silicone rescue tape around the the gap to seal it better, and the flow out of that vent got better.

Hmm, maybe I'll go wrap it with some gorilla tape and see if that fixes anything. A gap/leak is the only thing I can think of

I just had that piece of ducting out today. There seems to be a foam gasket on the piece for the left hand vent and the duct were not seated very well. I would take the one screw out and reseat the ducts and that may solve the problem.

Hope this helps,Ray.

I don't know how long gorilla tape lasts, but because I didn't want to go back and fix a conventional tape that dries out and falls apart, I did it with the [supposedly] permanent rescue tape. YMMV.

I do vaguely remember that foam piece and should have some stuff around here that could replace it pretty well. Thanks for the idea, I'll give it a shot too
Well I do have maybe 5 rolls of aviation tape laying around, might finally use some of that stuff instead

Fixed it! The duct wasn't sealing against the vent whatsoever in the back where it's not visible, had to really jiggle and wiggle it to get it to pop into place but now it's all sealed and blowing air wonderfully!

The deformation of the vents inside my dash was surprising to find when I ripped it all apart. I had to throttle and squeeze them like crazy to get them to seal again, but I think they are still leaking. Did you end up running a layer of tape on the outside of the vents when all was said and done?

That makes me feel better, it was an absolute pain to get it back in place again and I thought it was just me getting my ass kicked by 10 cents worth of plastic I just left it as is without any tape, in hindsight I probably could've but I was happy enough with the improvement that I called it good and moved on. Mine was clearly squished like it was jammed without much regard and not natural by any means - the previous owner definitely had it taken out to do some aftermarket alarm wiring at some point, and given his quality of work I've seen I'm not that surprised he managed to bungle something here too. However I definitely didn't help it by not catching it previously when I took it out myself, so I guess there's that too